Fix SDL colorspace matching AVCOL_SPC_RGB

Use BT.709 color space for AVCOL_SPC_RGB.

Refs #1868 comment <https://github.com/Genymobile/scrcpy/issues/1868#issuecomment-3293917796>

Signed-off-by: Romain Vimont <rom@rom1v.com>

app/src/audio_player.c

@@ -47,10 +47,7 @@ sc_audio_player_frame_sink_push(struct sc_frame_sink *sink,
 
 static bool
 sc_audio_player_frame_sink_open(struct sc_frame_sink *sink,
-                                const AVCodecContext *ctx,
-                                const struct sc_stream_session *session) {
-    (void) session;
-
+                                const AVCodecContext *ctx) {
     struct sc_audio_player *ap = DOWNCAST(sink);
 
 #ifdef SCRCPY_LAVU_HAS_CHLAYOUT

app/src/decoder.c

@@ -10,30 +10,20 @@
 #define DOWNCAST(SINK) container_of(SINK, struct sc_decoder, packet_sink)
 
 static bool
-sc_decoder_open(struct sc_decoder *decoder, AVCodecContext *ctx,
-                const struct sc_stream_session *session) {
+sc_decoder_open(struct sc_decoder *decoder, AVCodecContext *ctx) {
     decoder->frame = av_frame_alloc();
     if (!decoder->frame) {
         LOG_OOM();
         return false;
     }
 
-    if (!sc_frame_source_sinks_open(&decoder->frame_source, ctx, session)) {
+    if (!sc_frame_source_sinks_open(&decoder->frame_source, ctx)) {
         av_frame_free(&decoder->frame);
         return false;
     }
 
     decoder->ctx = ctx;
 
-    // A video stream must have a session
-    assert(session || ctx->codec_type != AVMEDIA_TYPE_VIDEO);
-
-    if (session) {
-        decoder->session = *session;
-    }
-
-    memset(&decoder->frame_size, 0, sizeof(decoder->frame_size));
-
     return true;
 }
 
@@ -71,32 +61,6 @@ sc_decoder_push(struct sc_decoder *decoder, const AVPacket *packet) {
         }
 
         // a frame was received
-
-        if (decoder->ctx->codec_type == AVMEDIA_TYPE_VIDEO) {
-            assert(decoder->frame->width >= 0);
-            assert(decoder->frame->height >= 0);
-            struct sc_size frame_size = {
-                .width = decoder->frame->width,
-                .height = decoder->frame->height,
-            };
-            if (decoder->frame_size.width != frame_size.width
-                    || decoder->frame_size.height != frame_size.height) {
-                // The frame size has changed, check if it matches the session
-                uint32_t sw = decoder->session.video.width;
-                uint32_t sh = decoder->session.video.height;
-                if (frame_size.width != sw || frame_size.height != sh) {
-                    LOGW("Unexpected video size: %" PRIu32 "x%" PRIu32
-                         " (expected %" PRIu32 "x%" PRIu32 ")",
-                         frame_size.width, frame_size.height, sw, sh);
-
-                    LOGW("The encoder did not respect the requested size, "
-                         "please retry with a lower resolution (-m/--max-size)");
-                }
-            }
-
-            decoder->frame_size = frame_size;
-        }
-
         bool ok = sc_frame_source_sinks_push(&decoder->frame_source,
                                              decoder->frame);
         av_frame_unref(decoder->frame);
@@ -110,17 +74,9 @@ sc_decoder_push(struct sc_decoder *decoder, const AVPacket *packet) {
 }
 
 static bool
-sc_decoder_push_session(struct sc_decoder *decoder,
-                        const struct sc_stream_session *session) {
-    decoder->session = *session;
-    return sc_frame_source_sinks_push_session(&decoder->frame_source, session);
-}
-
-static bool
-sc_decoder_packet_sink_open(struct sc_packet_sink *sink, AVCodecContext *ctx,
-                            const struct sc_stream_session *session) {
+sc_decoder_packet_sink_open(struct sc_packet_sink *sink, AVCodecContext *ctx) {
     struct sc_decoder *decoder = DOWNCAST(sink);
-    return sc_decoder_open(decoder, ctx, session);
+    return sc_decoder_open(decoder, ctx);
 }
 
 static void
@@ -136,14 +92,6 @@ sc_decoder_packet_sink_push(struct sc_packet_sink *sink,
     return sc_decoder_push(decoder, packet);
 }
 
-static bool
-sc_decoder_packet_sink_push_session(struct sc_packet_sink *sink,
-                                    const struct sc_stream_session *session) {
-
-    struct sc_decoder *decoder = DOWNCAST(sink);
-    return sc_decoder_push_session(decoder, session);
-}
-
 void
 sc_decoder_init(struct sc_decoder *decoder, const char *name) {
     decoder->name = name; // statically allocated
@@ -153,7 +101,6 @@ sc_decoder_init(struct sc_decoder *decoder, const char *name) {
         .open = sc_decoder_packet_sink_open,
         .close = sc_decoder_packet_sink_close,
         .push = sc_decoder_packet_sink_push,
-        .push_session = sc_decoder_packet_sink_push_session,
     };
 
     decoder->packet_sink.ops = &ops;

app/src/decoder.h

@@ -5,7 +5,6 @@
 
 #include <libavcodec/avcodec.h>
 
-#include "coords.h"
 #include "trait/frame_source.h"
 #include "trait/packet_sink.h"
 
@@ -17,9 +16,6 @@ struct sc_decoder {
 
     AVCodecContext *ctx;
     AVFrame *frame;
-
-    struct sc_stream_session session; // only initialized for video stream
-    struct sc_size frame_size;
 };
 
 // The name must be statically allocated (e.g. a string literal)

app/src/delay_buffer.c

@@ -10,18 +10,16 @@
 #define DOWNCAST(SINK) container_of(SINK, struct sc_delay_buffer, frame_sink)
 
 static bool
-sc_delayed_packet_init_frame(struct sc_delayed_packet *dpacket,
-                             const AVFrame *frame) {
-    dpacket->type = SC_DELAYED_PACKET_TYPE_FRAME;
-    dpacket->frame = av_frame_alloc();
-    if (!dpacket->frame) {
+sc_delayed_frame_init(struct sc_delayed_frame *dframe, const AVFrame *frame) {
+    dframe->frame = av_frame_alloc();
+    if (!dframe->frame) {
         LOG_OOM();
         return false;
     }
 
-    if (av_frame_ref(dpacket->frame, frame)) {
+    if (av_frame_ref(dframe->frame, frame)) {
         LOG_OOM();
-        av_frame_free(&dpacket->frame);
+        av_frame_free(&dframe->frame);
         return false;
     }
 
@@ -29,18 +27,9 @@ sc_delayed_packet_init_frame(struct sc_delayed_packet *dpacket,
 }
 
 static void
-sc_delayed_packet_init_session(struct sc_delayed_packet *dpacket,
-                               const struct sc_stream_session *session) {
-    dpacket->type = SC_DELAYED_PACKET_TYPE_SESSION;
-    dpacket->session = *session;
-}
-
-static void
-sc_delayed_packet_destroy(struct sc_delayed_packet *dpacket) {
-    if (dpacket->type == SC_DELAYED_PACKET_TYPE_FRAME) {
-        av_frame_unref(dpacket->frame);
-        av_frame_free(&dpacket->frame);
-    }
+sc_delayed_frame_destroy(struct sc_delayed_frame *dframe) {
+    av_frame_unref(dframe->frame);
+    av_frame_free(&dframe->frame);
 }
 
 static int
@@ -61,52 +50,43 @@ run_buffering(void *data) {
             goto stopped;
         }
 
-        struct sc_delayed_packet dpacket = sc_vecdeque_pop(&db->queue);
+        struct sc_delayed_frame dframe = sc_vecdeque_pop(&db->queue);
 
-        bool ok;
-        if (dpacket.type == SC_DELAYED_PACKET_TYPE_FRAME) {
-            sc_tick max_deadline = sc_tick_now() + db->delay;
-            // PTS (written by the server) are expressed in microseconds
-            sc_tick pts = SC_TICK_FROM_US(dpacket.frame->pts);
+        sc_tick max_deadline = sc_tick_now() + db->delay;
+        // PTS (written by the server) are expressed in microseconds
+        sc_tick pts = SC_TICK_FROM_US(dframe.frame->pts);
 
-            bool timed_out = false;
-            while (!db->stopped && !timed_out) {
-                sc_tick deadline = sc_clock_to_system_time(&db->clock, pts)
-                                 + db->delay;
-                if (deadline > max_deadline) {
-                    deadline = max_deadline;
-                }
-
-                timed_out =
-                    !sc_cond_timedwait(&db->wait_cond, &db->mutex, deadline);
+        bool timed_out = false;
+        while (!db->stopped && !timed_out) {
+            sc_tick deadline = sc_clock_to_system_time(&db->clock, pts)
+                             + db->delay;
+            if (deadline > max_deadline) {
+                deadline = max_deadline;
             }
 
-            bool stopped = db->stopped;
-            sc_mutex_unlock(&db->mutex);
-
-            if (stopped) {
-                sc_delayed_packet_destroy(&dpacket);
-                goto stopped;
-            }
-
-#ifdef SC_BUFFERING_DEBUG
-            LOGD("Buffering: %" PRItick ";%" PRItick ";%" PRItick,
-                 pts, dframe.push_date, sc_tick_now());
-#endif
-
-            ok = sc_frame_source_sinks_push(&db->frame_source, dpacket.frame);
-        } else {
-            assert(dpacket.type == SC_DELAYED_PACKET_TYPE_SESSION);
-            sc_mutex_unlock(&db->mutex);
-            ok = sc_frame_source_sinks_push_session(&db->frame_source,
-                                                    &dpacket.session);
+            timed_out =
+                !sc_cond_timedwait(&db->wait_cond, &db->mutex, deadline);
         }
 
-        sc_delayed_packet_destroy(&dpacket);
+        bool stopped = db->stopped;
+        sc_mutex_unlock(&db->mutex);
+
+        if (stopped) {
+            sc_delayed_frame_destroy(&dframe);
+            goto stopped;
+        }
+
+#ifdef SC_BUFFERING_DEBUG
+        LOGD("Buffering: %" PRItick ";%" PRItick ";%" PRItick,
+             pts, dframe.push_date, sc_tick_now());
+#endif
+
+        bool ok = sc_frame_source_sinks_push(&db->frame_source, dframe.frame);
+        sc_delayed_frame_destroy(&dframe);
         if (!ok) {
-            LOGE("Delayed packet could not be pushed, stopping");
+            LOGE("Delayed frame could not be pushed, stopping");
             sc_mutex_lock(&db->mutex);
-            // Prevent to push any new packet
+            // Prevent to push any new frame
             db->stopped = true;
             sc_mutex_unlock(&db->mutex);
             goto stopped;
@@ -118,8 +98,8 @@ stopped:
 
     // Flush queue
     while (!sc_vecdeque_is_empty(&db->queue)) {
-        struct sc_delayed_packet *dpacket = sc_vecdeque_popref(&db->queue);
-        sc_delayed_packet_destroy(dpacket);
+        struct sc_delayed_frame *dframe = sc_vecdeque_popref(&db->queue);
+        sc_delayed_frame_destroy(dframe);
     }
 
     LOGD("Buffering thread ended");
@@ -129,11 +109,9 @@ stopped:
 
 static bool
 sc_delay_buffer_frame_sink_open(struct sc_frame_sink *sink,
-                                const AVCodecContext *ctx,
-                                const struct sc_stream_session *session) {
+                                const AVCodecContext *ctx) {
     struct sc_delay_buffer *db = DOWNCAST(sink);
     (void) ctx;
-    (void) session;
 
     bool ok = sc_mutex_init(&db->mutex);
     if (!ok) {
@@ -154,7 +132,7 @@ sc_delay_buffer_frame_sink_open(struct sc_frame_sink *sink,
     sc_vecdeque_init(&db->queue);
     db->stopped = false;
 
-    if (!sc_frame_source_sinks_open(&db->frame_source, ctx, session)) {
+    if (!sc_frame_source_sinks_open(&db->frame_source, ctx)) {
         goto error_destroy_wait_cond;
     }
 
@@ -218,56 +196,24 @@ sc_delay_buffer_frame_sink_push(struct sc_frame_sink *sink,
         return sc_frame_source_sinks_push(&db->frame_source, frame);
     }
 
-    struct sc_delayed_packet *dpacket = sc_vecdeque_push_hole(&db->queue);
-    if (!dpacket) {
+    struct sc_delayed_frame dframe;
+    bool ok = sc_delayed_frame_init(&dframe, frame);
+    if (!ok) {
         sc_mutex_unlock(&db->mutex);
-        LOG_OOM();
         return false;
     }
 
-    bool ok = sc_delayed_packet_init_frame(dpacket, frame);
+#ifdef SC_BUFFERING_DEBUG
+    dframe.push_date = sc_tick_now();
+#endif
+
+    ok = sc_vecdeque_push(&db->queue, dframe);
     if (!ok) {
         sc_mutex_unlock(&db->mutex);
         LOG_OOM();
         return false;
     }
 
-#ifdef SC_BUFFERING_DEBUG
-    dpacket->push_date = sc_tick_now();
-#endif
-
-    sc_cond_signal(&db->queue_cond);
-
-    sc_mutex_unlock(&db->mutex);
-
-    return true;
-}
-
-static bool
-sc_delay_buffer_frame_sink_push_session(struct sc_frame_sink *sink,
-                                      const struct sc_stream_session *session) {
-    struct sc_delay_buffer *db = DOWNCAST(sink);
-
-    sc_mutex_lock(&db->mutex);
-
-    if (db->stopped) {
-        sc_mutex_unlock(&db->mutex);
-        return false;
-    }
-
-    struct sc_delayed_packet *dpacket = sc_vecdeque_push_hole(&db->queue);
-    if (!dpacket) {
-        sc_mutex_unlock(&db->mutex);
-        LOG_OOM();
-        return false;
-    }
-
-    sc_delayed_packet_init_session(dpacket, session);
-
-#ifdef SC_BUFFERING_DEBUG
-    dpacket->push_date = sc_tick_now();
-#endif
-
     sc_cond_signal(&db->queue_cond);
 
     sc_mutex_unlock(&db->mutex);
@@ -289,7 +235,6 @@ sc_delay_buffer_init(struct sc_delay_buffer *db, sc_tick delay,
         .open = sc_delay_buffer_frame_sink_open,
         .close = sc_delay_buffer_frame_sink_close,
         .push = sc_delay_buffer_frame_sink_push,
-        .push_session = sc_delay_buffer_frame_sink_push_session,
     };
 
     db->frame_sink.ops = &ops;

app/src/delay_buffer.h

@@ -18,23 +18,14 @@
 // forward declarations
 typedef struct AVFrame AVFrame;
 
-enum sc_delayed_packet_type {
-    SC_DELAYED_PACKET_TYPE_FRAME,
-    SC_DELAYED_PACKET_TYPE_SESSION,
-};
-
-struct sc_delayed_packet {
-    enum sc_delayed_packet_type type;
-    union {
-        AVFrame *frame;
-        struct sc_stream_session session;
-    };
+struct sc_delayed_frame {
+    AVFrame *frame;
 #ifdef SC_BUFFERING_DEBUG
     sc_tick push_date;
 #endif
 };
 
-struct sc_delayed_packet_queue SC_VECDEQUE(struct sc_delayed_packet);
+struct sc_delayed_frame_queue SC_VECDEQUE(struct sc_delayed_frame);
 
 struct sc_delay_buffer {
     struct sc_frame_source frame_source; // frame source trait
@@ -49,7 +40,7 @@ struct sc_delay_buffer {
     sc_cond wait_cond;
 
     struct sc_clock clock;
-    struct sc_delayed_packet_queue queue;
+    struct sc_delayed_frame_queue queue;
     bool stopped;
 };
 

app/src/demuxer.c

@@ -11,8 +11,8 @@
 
 #define SC_PACKET_HEADER_SIZE 12
 
-#define SC_PACKET_FLAG_CONFIG    (UINT64_C(1) << 62)
-#define SC_PACKET_FLAG_KEY_FRAME (UINT64_C(1) << 61)
+#define SC_PACKET_FLAG_CONFIG    (UINT64_C(1) << 63)
+#define SC_PACKET_FLAG_KEY_FRAME (UINT64_C(1) << 62)
 
 #define SC_PACKET_PTS_MASK (SC_PACKET_FLAG_KEY_FRAME - 1)
 
@@ -63,75 +63,48 @@ sc_demuxer_recv_codec_id(struct sc_demuxer *demuxer, uint32_t *codec_id) {
     return true;
 }
 
-static inline bool
-sc_demuxer_recv_header(struct sc_demuxer *demuxer,
-                       uint8_t buf[static SC_PACKET_HEADER_SIZE]) {
+static bool
+sc_demuxer_recv_video_size(struct sc_demuxer *demuxer, uint32_t *width,
+                           uint32_t *height) {
+    uint8_t data[8];
+    ssize_t r = net_recv_all(demuxer->socket, data, 8);
+    if (r < 8) {
+        return false;
+    }
+
+    *width = sc_read32be(data);
+    *height = sc_read32be(data + 4);
+    return true;
+}
+
+static bool
+sc_demuxer_recv_packet(struct sc_demuxer *demuxer, AVPacket *packet) {
     // The video and audio streams contain a sequence of raw packets (as
     // provided by MediaCodec), each prefixed with a "meta" header.
     //
-    // The "meta" header length is 12 bytes.
-    //
-    //
-    // If the MSB is 1, then it is a session packet (for a video stream only),
-    // which only contains a 12-byte header:
-    //
-    //  byte 0   byte 1   byte 2   byte 3
-    // 10000000 00000000 00000000 00000000
-    // ^<-------------------------------->
-    // |               padding
-    //  `- session packet flag
-    //
-    //  byte 4   byte 5   byte 6   byte 7   byte 8   byte 9   byte 10  byte 11
-    // ........ ........ ........ ........ ........ ........ ........ ........
-    // <---------------------------------> <--------------------------------->
-    //             video width                         video height
-    //
-    //
-    // If the MSB is 0, then it is a media packet, comprised of a 12-byte header
-    // followed by <packet_size> bytes containing the packet/frame:
-    //
+    // The "meta" header length is 12 bytes:
     // [. . . . . . . .|. . . .]. . . . . . . . . . . . . . . ...
     //  <-------------> <-----> <-----------------------------...
     //        PTS        packet        raw packet
     //                    size
     //
+    // It is followed by <packet_size> bytes containing the packet/frame.
+    //
     // The most significant bits of the PTS are used for packet flags:
     //
-    //  byte 0   byte 1   byte 2   byte 3   byte 4   byte 5   byte 6   byte 7
-    // 0CK..... ........ ........ ........ ........ ........ ........ ........
-    // ^^^<------------------------------------------------------------------>
-    // |||                                PTS
-    // || `- key frame
-    // | `-- config packet
-    //  `--- media packet flag
-    //
-    //  byte 8   byte 9   byte 10  byte 11
-    // ........ ........ ........ ........ ........ ........ . . .
-    // <---------------------------------> <---------------- . . .
-    //            packet size                       raw packet
-    //
-    ssize_t r = net_recv_all(demuxer->socket, buf, SC_PACKET_HEADER_SIZE);
-    assert(r <= SC_PACKET_HEADER_SIZE);
-    return r == SC_PACKET_HEADER_SIZE;
-}
+    //  byte 7   byte 6   byte 5   byte 4   byte 3   byte 2   byte 1   byte 0
+    // CK...... ........ ........ ........ ........ ........ ........ ........
+    // ^^<------------------------------------------------------------------->
+    // ||                                PTS
+    // | `- key frame
+    //  `-- config packet
 
-static bool
-sc_demuxer_is_session(const uint8_t *header) {
-    return header[0] & 0x80;
-}
+    uint8_t header[SC_PACKET_HEADER_SIZE];
+    ssize_t r = net_recv_all(demuxer->socket, header, SC_PACKET_HEADER_SIZE);
+    if (r < SC_PACKET_HEADER_SIZE) {
+        return false;
+    }
 
-static void
-sc_demuxer_parse_session(const uint8_t *header,
-                         struct sc_stream_session *session) {
-    assert(sc_demuxer_is_session(header));
-    session->video.width = sc_read32be(&header[4]);
-    session->video.height = sc_read32be(&header[8]);
-}
-
-static bool
-sc_demuxer_recv_packet(struct sc_demuxer *demuxer, const uint8_t *header,
-                       AVPacket *packet) {
-    assert(!sc_demuxer_is_session(header));
     uint64_t pts_flags = sc_read64be(header);
     uint32_t len = sc_read32be(&header[8]);
     assert(len);
@@ -141,7 +114,7 @@ sc_demuxer_recv_packet(struct sc_demuxer *demuxer, const uint8_t *header,
         return false;
     }
 
-    ssize_t r = net_recv_all(demuxer->socket, packet->data, len);
+    r = net_recv_all(demuxer->socket, packet->data, len);
     if (r < 0 || ((uint32_t) r) < len) {
         av_packet_unref(packet);
         return false;
@@ -214,28 +187,17 @@ run_demuxer(void *data) {
 
     codec_ctx->flags |= AV_CODEC_FLAG_LOW_DELAY;
 
-    uint8_t header[SC_PACKET_HEADER_SIZE];
-    struct sc_stream_session session_data;
-
-    struct sc_stream_session *session = NULL;
     if (codec->type == AVMEDIA_TYPE_VIDEO) {
-        bool ok = sc_demuxer_recv_header(demuxer, header);
+        uint32_t width;
+        uint32_t height;
+        ok = sc_demuxer_recv_video_size(demuxer, &width, &height);
         if (!ok) {
             goto finally_free_context;
         }
 
-        if (!sc_demuxer_is_session(header)) {
-            LOGE("Unexpected packet (not a session header)");
-            goto finally_free_context;
-        }
-
-        session = &session_data;
-        sc_demuxer_parse_session(header, session);
-
-        codec_ctx->width = session_data.video.width;
-        codec_ctx->height = session_data.video.height;
+        codec_ctx->width = width;
+        codec_ctx->height = height;
         codec_ctx->pix_fmt = AV_PIX_FMT_YUV420P;
-
     } else {
         // Hardcoded audio properties
 #ifdef SCRCPY_LAVU_HAS_CHLAYOUT
@@ -257,8 +219,7 @@ run_demuxer(void *data) {
         goto finally_free_context;
     }
 
-    if (!sc_packet_source_sinks_open(&demuxer->packet_source, codec_ctx,
-                                     session)) {
+    if (!sc_packet_source_sinks_open(&demuxer->packet_source, codec_ctx)) {
         goto finally_free_context;
     }
 
@@ -280,39 +241,27 @@ run_demuxer(void *data) {
     }
 
     for (;;) {
-        bool ok = sc_demuxer_recv_header(demuxer, header);
+        bool ok = sc_demuxer_recv_packet(demuxer, packet);
         if (!ok) {
             // end of stream
             status = SC_DEMUXER_STATUS_EOS;
             break;
         }
 
-        if (sc_demuxer_is_session(header)) {
-            sc_demuxer_parse_session(header, &session_data);
-            ok = sc_packet_source_sinks_push_session(&demuxer->packet_source,
-                                                     &session_data);
+        if (must_merge_config_packet) {
+            // Prepend any config packet to the next media packet
+            ok = sc_packet_merger_merge(&merger, packet);
             if (!ok) {
-                // The sink already logged its concrete error
+                av_packet_unref(packet);
                 break;
             }
-        } else {
-            sc_demuxer_recv_packet(demuxer, header, packet);
+        }
 
-            if (must_merge_config_packet) {
-                // Prepend any config packet to the next media packet
-                ok = sc_packet_merger_merge(&merger, packet);
-                if (!ok) {
-                    av_packet_unref(packet);
-                    break;
-                }
-            }
-
-            ok = sc_packet_source_sinks_push(&demuxer->packet_source, packet);
-            av_packet_unref(packet);
-            if (!ok) {
-                // The sink already logged its concrete error
-                break;
-            }
+        ok = sc_packet_source_sinks_push(&demuxer->packet_source, packet);
+        av_packet_unref(packet);
+        if (!ok) {
+            // The sink already logged its concrete error
+            break;
         }
     }
 

app/src/display.c

@@ -6,6 +6,7 @@
 #include <libavutil/pixfmt.h>
 
 #include "util/log.h"
+#include "util/window.h"
 
 static bool
 sc_display_init_novideo_icon(struct sc_display *display,
@@ -374,9 +375,7 @@ sc_display_update_texture(struct sc_display *display, const AVFrame *frame) {
 enum sc_display_result
 sc_display_render(struct sc_display *display, const SDL_Rect *geometry,
                   enum sc_orientation orientation) {
-    bool always_ok = SDL_RenderClear(display->renderer);
-    (void) always_ok;
-    assert(always_ok);
+    sc_sdl_render_clear(display->renderer);
 
     if (display->pending.flags) {
         bool ok = sc_display_apply_pending(display);
@@ -421,8 +420,6 @@ sc_display_render(struct sc_display *display, const SDL_Rect *geometry,
         }
     }
 
-    always_ok = SDL_RenderPresent(display->renderer);
-    assert(always_ok);
-
+    sc_sdl_render_present(display->renderer);
     return SC_DISPLAY_RESULT_OK;
 }

app/src/input_manager.c

@@ -11,6 +11,7 @@
 #include "screen.h"
 #include "shortcut_mod.h"
 #include "util/log.h"
+#include "util/window.h"
 
 void
 sc_input_manager_init(struct sc_input_manager *im,
@@ -672,15 +673,12 @@ sc_input_manager_process_touch(struct sc_input_manager *im,
         return;
     }
 
-    int dw;
-    int dh;
-    bool always_ok = SDL_GetWindowSizeInPixels(im->screen->window, &dw, &dh);
-    (void) always_ok;
-    assert(always_ok);
+    struct sc_size drawable_size =
+        sc_sdl_get_window_size_in_pixels(im->screen->window);
 
     // SDL touch event coordinates are normalized in the range [0; 1]
-    int32_t x = event->x * dw;
-    int32_t y = event->y * dh;
+    int32_t x = event->x * (int32_t) drawable_size.width;
+    int32_t y = event->y * (int32_t) drawable_size.height;
 
     struct sc_touch_event evt = {
         .position = {

app/src/recorder.c

@@ -541,10 +541,7 @@ sc_recorder_set_orientation(AVStream *stream, enum sc_orientation orientation) {
 
 static bool
 sc_recorder_video_packet_sink_open(struct sc_packet_sink *sink,
-                                   AVCodecContext *ctx,
-                                   const struct sc_stream_session *session) {
-    (void) session;
-
+                                   AVCodecContext *ctx) {
     struct sc_recorder *recorder = DOWNCAST_VIDEO(sink);
     // only written from this thread, no need to lock
     assert(!recorder->video_init);
@@ -638,10 +635,7 @@ sc_recorder_video_packet_sink_push(struct sc_packet_sink *sink,
 
 static bool
 sc_recorder_audio_packet_sink_open(struct sc_packet_sink *sink,
-                                   AVCodecContext *ctx,
-                                   const struct sc_stream_session *session) {
-    (void) session;
-
+                                   AVCodecContext *ctx) {
     struct sc_recorder *recorder = DOWNCAST_AUDIO(sink);
     assert(recorder->audio);
     // only written from this thread, no need to lock

app/src/screen.c

@@ -9,6 +9,7 @@
 #include "options.h"
 #include "util/log.h"
 #include "util/window.h"
+#include "util/window.h"
 
 #define DISPLAY_MARGINS 96
 
@@ -27,45 +28,12 @@ get_oriented_size(struct sc_size size, enum sc_orientation orientation) {
     return oriented_size;
 }
 
-// get the window size in a struct sc_size
-static struct sc_size
-get_window_size(const struct sc_screen *screen) {
-    int width;
-    int height;
-    bool always_ok = SDL_GetWindowSize(screen->window, &width, &height);
-    (void) always_ok;
-    assert(always_ok);
-
-    struct sc_size size;
-    size.width = width;
-    size.height = height;
-    return size;
-}
-
-static struct sc_point
-get_window_position(const struct sc_screen *screen) {
-    int x;
-    int y;
-    bool always_ok = SDL_GetWindowPosition(screen->window, &x, &y);
-    (void) always_ok;
-    assert(always_ok);
-
-    struct sc_point point;
-    point.x = x;
-    point.y = y;
-    return point;
-}
-
 // set the window size to be applied when fullscreen is disabled
-static void
-set_window_size(struct sc_screen *screen, struct sc_size new_size) {
+static inline void
+assert_not_fullscreen(struct sc_screen *screen) {
     assert(!screen->fullscreen);
     assert(!screen->maximized);
     assert(!screen->minimized);
-    bool always_ok =
-        SDL_SetWindowSize(screen->window, new_size.width, new_size.height);
-    (void) always_ok;
-    assert(always_ok);
 }
 
 // get the preferred display bounds (i.e. the screen bounds with some margins)
@@ -176,15 +144,10 @@ static void
 sc_screen_update_content_rect(struct sc_screen *screen) {
     assert(screen->video);
 
-    int dw;
-    int dh;
-    bool always_ok = SDL_GetWindowSizeInPixels(screen->window, &dw, &dh);
-    (void) always_ok;
-    assert(always_ok);
-
     struct sc_size content_size = screen->content_size;
     // The drawable size is the window size * the HiDPI scale
-    struct sc_size drawable_size = {dw, dh};
+    struct sc_size drawable_size =
+        sc_sdl_get_window_size_in_pixels(screen->window);
 
     SDL_Rect *rect = &screen->rect;
 
@@ -265,11 +228,9 @@ event_watcher(void *data, SDL_Event *event) {
 
 static bool
 sc_screen_frame_sink_open(struct sc_frame_sink *sink,
-                          const AVCodecContext *ctx,
-                          const struct sc_stream_session *session) {
+                          const AVCodecContext *ctx) {
     assert(ctx->pix_fmt == AV_PIX_FMT_YUV420P);
     (void) ctx;
-    (void) session;
 
     struct sc_screen *screen = DOWNCAST(sink);
     (void) screen;
@@ -399,7 +360,7 @@ sc_screen_init(struct sc_screen *screen,
 
     // The window will be positioned and sized on first video frame
     screen->window =
-        sc_create_sdl_window(title, x, y, width, height, window_flags);
+        sc_sdl_create_window(title, x, y, width, height, window_flags);
     if (!screen->window) {
         LOGE("Could not create window: %s", SDL_GetError());
         goto error_destroy_fps_counter;
@@ -507,18 +468,18 @@ sc_screen_show_initial_window(struct sc_screen *screen) {
           ? screen->req.x : (int) SDL_WINDOWPOS_CENTERED;
     int y = screen->req.y != SC_WINDOW_POSITION_UNDEFINED
           ? screen->req.y : (int) SDL_WINDOWPOS_CENTERED;
+    struct sc_point position = {
+        .x = x,
+        .y = y,
+    };
 
     struct sc_size window_size =
         get_initial_optimal_size(screen->content_size, screen->req.width,
                                                        screen->req.height);
 
-    set_window_size(screen, window_size);
-
-    bool always_ok;
-    (void) always_ok;
-
-    always_ok = SDL_SetWindowPosition(screen->window, x, y);
-    assert(always_ok);
+    assert_not_fullscreen(screen);
+    sc_sdl_set_window_size(screen->window, window_size);
+    sc_sdl_set_window_position(screen->window, position);
 
     if (screen->req.fullscreen) {
         sc_screen_toggle_fullscreen(screen);
@@ -528,17 +489,13 @@ sc_screen_show_initial_window(struct sc_screen *screen) {
         sc_fps_counter_start(&screen->fps_counter);
     }
 
-    always_ok = SDL_ShowWindow(screen->window);
-    assert(always_ok);
-
+    sc_sdl_show_window(screen->window);
     sc_screen_update_content_rect(screen);
 }
 
 void
 sc_screen_hide_window(struct sc_screen *screen) {
-    bool always_ok = SDL_HideWindow(screen->window);
-    (void) always_ok;
-    assert(always_ok);
+    sc_sdl_hide_window(screen->window);
 }
 
 void
@@ -568,7 +525,7 @@ resize_for_content(struct sc_screen *screen, struct sc_size old_content_size,
                    struct sc_size new_content_size) {
     assert(screen->video);
 
-    struct sc_size window_size = get_window_size(screen);
+    struct sc_size window_size = sc_sdl_get_window_size(screen->window);
     struct sc_size target_size = {
         .width = (uint32_t) window_size.width * new_content_size.width
                 / old_content_size.width,
@@ -576,7 +533,8 @@ resize_for_content(struct sc_screen *screen, struct sc_size old_content_size,
                 / old_content_size.height,
     };
     target_size = get_optimal_size(target_size, new_content_size, true);
-    set_window_size(screen, target_size);
+    assert_not_fullscreen(screen);
+    sc_sdl_set_window_size(screen->window, target_size);
 }
 
 static void
@@ -772,8 +730,8 @@ sc_screen_resize_to_fit(struct sc_screen *screen) {
         return;
     }
 
-    struct sc_point point = get_window_position(screen);
-    struct sc_size window_size = get_window_size(screen);
+    struct sc_point point = sc_sdl_get_window_position(screen->window);
+    struct sc_size window_size = sc_sdl_get_window_size(screen->window);
 
     struct sc_size optimal_size =
         get_optimal_size(window_size, screen->content_size, false);
@@ -781,19 +739,14 @@ sc_screen_resize_to_fit(struct sc_screen *screen) {
     // Center the window related to the device screen
     assert(optimal_size.width <= window_size.width);
     assert(optimal_size.height <= window_size.height);
-    uint32_t new_x = point.x + (window_size.width - optimal_size.width) / 2;
-    uint32_t new_y = point.y + (window_size.height - optimal_size.height) / 2;
 
-    bool always_ok;
-    (void) always_ok;
-
-    always_ok = SDL_SetWindowSize(screen->window, optimal_size.width,
-                                                  optimal_size.height);
-    assert(always_ok);
-
-    always_ok = SDL_SetWindowPosition(screen->window, new_x, new_y);
-    assert(always_ok);
+    struct sc_point new_position = {
+        .x = point.x + (window_size.width - optimal_size.width) / 2,
+        .y = point.y + (window_size.height - optimal_size.height) / 2,
+    };
 
+    sc_sdl_set_window_size(screen->window, optimal_size);
+    sc_sdl_set_window_position(screen->window, new_position);
     LOGD("Resized to optimal size: %ux%u", optimal_size.width,
                                            optimal_size.height);
 }
@@ -806,20 +759,13 @@ sc_screen_resize_to_pixel_perfect(struct sc_screen *screen) {
         return;
     }
 
-    bool always_ok;
-    (void) always_ok;
-
     if (screen->maximized) {
-        always_ok = SDL_RestoreWindow(screen->window);
-        assert(always_ok);
+        sc_sdl_restore_window(screen->window);
         screen->maximized = false;
     }
 
     struct sc_size content_size = screen->content_size;
-    always_ok = SDL_SetWindowSize(screen->window, content_size.width,
-                                                  content_size.height);
-    assert(always_ok);
-
+    sc_sdl_set_window_size(screen->window, content_size);
     LOGD("Resized to pixel-perfect: %ux%u", content_size.width,
                                             content_size.height);
 }
@@ -948,16 +894,16 @@ sc_screen_convert_window_to_frame_coords(struct sc_screen *screen,
 
 void
 sc_screen_hidpi_scale_coords(struct sc_screen *screen, int32_t *x, int32_t *y) {
-    bool always_ok;
-    (void) always_ok;
-
     // take the HiDPI scaling (dw/ww and dh/wh) into account
-    int ww, wh, dw, dh;
-    always_ok = SDL_GetWindowSize(screen->window, &ww, &wh);
-    assert(always_ok);
 
-    always_ok = SDL_GetWindowSizeInPixels(screen->window, &dw, &dh);
-    assert(always_ok);
+    struct sc_size window_size = sc_sdl_get_window_size(screen->window);
+    int64_t ww = window_size.width;
+    int64_t wh = window_size.height;
+
+    struct sc_size drawable_size =
+        sc_sdl_get_window_size_in_pixels(screen->window);
+    int64_t dw = drawable_size.width;
+    int64_t dh = drawable_size.height;
 
     // scale for HiDPI (64 bits for intermediate multiplications)
     *x = (int64_t) *x * dw / ww;

app/src/trait/frame_sink.h

@@ -6,8 +6,6 @@
 #include <stdbool.h>
 #include <libavcodec/avcodec.h>
 
-#include "trait/packet_sink.h"
-
 /**
  * Frame sink trait.
  *
@@ -19,16 +17,9 @@ struct sc_frame_sink {
 
 struct sc_frame_sink_ops {
     /* The codec context is valid until the sink is closed */
-    bool (*open)(struct sc_frame_sink *sink, const AVCodecContext *ctx,
-                 const struct sc_stream_session *session);
+    bool (*open)(struct sc_frame_sink *sink, const AVCodecContext *ctx);
     void (*close)(struct sc_frame_sink *sink);
     bool (*push)(struct sc_frame_sink *sink, const AVFrame *frame);
-
-    /**
-     * Optional callback to be notified of a new stream session.
-     */
-    bool (*push_session)(struct sc_frame_sink *sink,
-                         const struct sc_stream_session *session);
 };
 
 #endif

app/src/trait/frame_source.c

@@ -27,12 +27,11 @@ sc_frame_source_sinks_close_firsts(struct sc_frame_source *source,
 
 bool
 sc_frame_source_sinks_open(struct sc_frame_source *source,
-                           const AVCodecContext *ctx,
-                           const struct sc_stream_session *session) {
+                           const AVCodecContext *ctx) {
     assert(source->sink_count);
     for (unsigned i = 0; i < source->sink_count; ++i) {
         struct sc_frame_sink *sink = source->sinks[i];
-        if (!sink->ops->open(sink, ctx, session)) {
+        if (!sink->ops->open(sink, ctx)) {
             sc_frame_source_sinks_close_firsts(source, i);
             return false;
         }
@@ -60,18 +59,3 @@ sc_frame_source_sinks_push(struct sc_frame_source *source,
 
     return true;
 }
-
-bool
-sc_frame_source_sinks_push_session(struct sc_frame_source *source,
-                                   const struct sc_stream_session *session) {
-    assert(source->sink_count);
-    for (unsigned i = 0; i < source->sink_count; ++i) {
-        struct sc_frame_sink *sink = source->sinks[i];
-        if (sink->ops->push_session &&
-                !sink->ops->push_session(sink, session)) {
-            return false;
-        }
-    }
-
-    return true;
-}

app/src/trait/frame_source.h

@@ -28,8 +28,7 @@ sc_frame_source_add_sink(struct sc_frame_source *source,
 
 bool
 sc_frame_source_sinks_open(struct sc_frame_source *source,
-                           const AVCodecContext *ctx,
-                           const struct sc_stream_session *session);
+                           const AVCodecContext *ctx);
 
 void
 sc_frame_source_sinks_close(struct sc_frame_source *source);
@@ -38,8 +37,4 @@ bool
 sc_frame_source_sinks_push(struct sc_frame_source *source,
                            const AVFrame *frame);
 
-bool
-sc_frame_source_sinks_push_session(struct sc_frame_source *source,
-                                   const struct sc_stream_session *session);
-
 #endif

app/src/trait/packet_sink.h

@@ -15,28 +15,12 @@ struct sc_packet_sink {
     const struct sc_packet_sink_ops *ops;
 };
 
-struct sc_stream_session_video {
-    uint32_t width;
-    uint32_t height;
-};
-
-struct sc_stream_session {
-    struct sc_stream_session_video video;
-};
-
 struct sc_packet_sink_ops {
     /* The codec context is valid until the sink is closed */
-    bool (*open)(struct sc_packet_sink *sink, AVCodecContext *ctx,
-                 const struct sc_stream_session *session);
+    bool (*open)(struct sc_packet_sink *sink, AVCodecContext *ctx);
     void (*close)(struct sc_packet_sink *sink);
     bool (*push)(struct sc_packet_sink *sink, const AVPacket *packet);
 
-    /**
-     * Optional callback to be notified of a new stream session.
-     */
-    bool (*push_session)(struct sc_packet_sink *sink,
-                         const struct sc_stream_session *session);
-
     /*/
      * Called when the input stream has been disabled at runtime.
      *

app/src/trait/packet_source.c

@@ -27,12 +27,11 @@ sc_packet_source_sinks_close_firsts(struct sc_packet_source *source,
 
 bool
 sc_packet_source_sinks_open(struct sc_packet_source *source,
-                            AVCodecContext *ctx,
-                            const struct sc_stream_session *session) {
+                            AVCodecContext *ctx) {
     assert(source->sink_count);
     for (unsigned i = 0; i < source->sink_count; ++i) {
         struct sc_packet_sink *sink = source->sinks[i];
-        if (!sink->ops->open(sink, ctx, session)) {
+        if (!sink->ops->open(sink, ctx)) {
             sc_packet_source_sinks_close_firsts(source, i);
             return false;
         }
@@ -61,20 +60,6 @@ sc_packet_source_sinks_push(struct sc_packet_source *source,
     return true;
 }
 
-bool
-sc_packet_source_sinks_push_session(struct sc_packet_source *source,
-                                    const struct sc_stream_session *session) {
-    assert(source->sink_count);
-    for (unsigned i = 0; i < source->sink_count; ++i) {
-        struct sc_packet_sink *sink = source->sinks[i];
-        if (!sink->ops->push_session(sink, session)) {
-            return false;
-        }
-    }
-
-    return true;
-}
-
 void
 sc_packet_source_sinks_disable(struct sc_packet_source *source) {
     assert(source->sink_count);

app/src/trait/packet_source.h

@@ -28,8 +28,7 @@ sc_packet_source_add_sink(struct sc_packet_source *source,
 
 bool
 sc_packet_source_sinks_open(struct sc_packet_source *source,
-                            AVCodecContext *ctx,
-                            const struct sc_stream_session *session);
+                            AVCodecContext *ctx);
 
 void
 sc_packet_source_sinks_close(struct sc_packet_source *source);
@@ -38,10 +37,6 @@ bool
 sc_packet_source_sinks_push(struct sc_packet_source *source,
                             const AVPacket *packet);
 
-bool
-sc_packet_source_sinks_push_session(struct sc_packet_source *source,
-                                    const struct sc_stream_session *session);
-
 void
 sc_packet_source_sinks_disable(struct sc_packet_source *source);
 

app/src/usb/screen_otg.c

@@ -11,10 +11,7 @@
 
 static void
 sc_screen_otg_render(struct sc_screen_otg *screen) {
-    bool always_ok = SDL_RenderClear(screen->renderer);
-    (void) always_ok;
-    assert(always_ok);
-
+    sc_sdl_render_clear(screen->renderer);
     if (screen->texture) {
         bool ok =
             SDL_RenderTexture(screen->renderer, screen->texture, NULL, NULL);
@@ -22,9 +19,7 @@ sc_screen_otg_render(struct sc_screen_otg *screen) {
             LOGW("Could not render texture: %s", SDL_GetError());
         }
     }
-
-    always_ok = SDL_RenderPresent(screen->renderer);
-    assert(always_ok);
+    sc_sdl_render_present(screen->renderer);
 }
 
 bool
@@ -53,7 +48,7 @@ sc_screen_otg_init(struct sc_screen_otg *screen,
     }
 
     screen->window =
-        sc_create_sdl_window(title, x, y, width, height, window_flags);
+        sc_sdl_create_window(title, x, y, width, height, window_flags);
     if (!screen->window) {
         LOGE("Could not create window: %s", SDL_GetError());
         return false;

app/src/util/window.c

@@ -1,7 +1,12 @@
 #include "window.h"
 
+#include <assert.h>
+#include <stdlib.h>
+
+#include "util/log.h"
+
 SDL_Window *
-sc_create_sdl_window(const char *title, int64_t x, int64_t y, int64_t width,
+sc_sdl_create_window(const char *title, int64_t x, int64_t y, int64_t width,
                      int64_t height, int64_t flags) {
     SDL_Window *window = NULL;
 
@@ -31,3 +36,123 @@ sc_create_sdl_window(const char *title, int64_t x, int64_t y, int64_t width,
     SDL_DestroyProperties(props);
     return window;
 }
+
+struct sc_size
+sc_sdl_get_window_size(SDL_Window *window) {
+    int width;
+    int height;
+    bool ok = SDL_GetWindowSize(window, &width, &height);
+    if (!ok) {
+        LOGE("Could not get window size: %s", SDL_GetError());
+        LOGE("Please report the error");
+        // fatal error
+        abort();
+    }
+
+    struct sc_size size = {
+        .width = width,
+        .height = height,
+    };
+    return size;
+}
+
+struct sc_size
+sc_sdl_get_window_size_in_pixels(SDL_Window *window) {
+    int width;
+    int height;
+    bool ok = SDL_GetWindowSizeInPixels(window, &width, &height);
+    if (!ok) {
+        LOGE("Could not get window size: %s", SDL_GetError());
+        LOGE("Please report the error");
+        // fatal error
+        abort();
+    }
+
+    struct sc_size size = {
+        .width = width,
+        .height = height,
+    };
+    return size;
+}
+
+void
+sc_sdl_set_window_size(SDL_Window *window, struct sc_size size) {
+    bool ok = SDL_SetWindowSize(window, size.width, size.height);
+    if (!ok) {
+        LOGE("Could not set window size: %s", SDL_GetError());
+        assert(!"unexpected");
+    }
+}
+
+struct sc_point
+sc_sdl_get_window_position(SDL_Window *window) {
+    int x;
+    int y;
+    bool ok = SDL_GetWindowPosition(window, &x, &y);
+    if (!ok) {
+        LOGE("Could not get window position: %s", SDL_GetError());
+        LOGE("Please report the error");
+        // fatal error
+        abort();
+    }
+
+    struct sc_point point = {
+        .x = x,
+        .y = y,
+    };
+    return point;
+}
+
+void
+sc_sdl_set_window_position(SDL_Window *window, struct sc_point point) {
+    bool ok = SDL_SetWindowPosition(window, point.x, point.y);
+    if (!ok) {
+        LOGE("Could not set window position: %s", SDL_GetError());
+        assert(!"unexpected");
+    }
+}
+
+void
+sc_sdl_show_window(SDL_Window *window) {
+    bool ok = SDL_ShowWindow(window);
+    if (!ok) {
+        LOGE("Could not show window: %s", SDL_GetError());
+        assert(!"unexpected");
+    }
+}
+
+void
+sc_sdl_hide_window(SDL_Window *window) {
+    bool ok = SDL_HideWindow(window);
+    if (!ok) {
+        LOGE("Could not hide window: %s", SDL_GetError());
+        assert(!"unexpected");
+    }
+}
+
+void
+sc_sdl_restore_window(SDL_Window *window) {
+    bool ok = SDL_RestoreWindow(window);
+    if (!ok) {
+        LOGE("Could not restore window: %s", SDL_GetError());
+        assert(!"unexpected");
+    }
+}
+
+bool
+sc_sdl_render_clear(SDL_Renderer *renderer) {
+    bool ok = SDL_RenderClear(renderer);
+    if (!ok) {
+        LOGW("Could not clear rendering: %s", SDL_GetError());
+    }
+    return ok;
+}
+
+void
+sc_sdl_render_present(SDL_Renderer *renderer) {
+    bool ok = SDL_RenderPresent(renderer);
+    if (!ok) {
+        LOGE("Could not render: %s", SDL_GetError());
+        assert(!"unexpected");
+    }
+}

app/src/util/window.h

@@ -4,10 +4,43 @@
 #include "common.h"
 
 #include <stdint.h>
+#include <SDL3/SDL_render.h>
 #include <SDL3/SDL_video.h>
 
+#include "coords.h"
+
 SDL_Window *
-sc_create_sdl_window(const char *title, int64_t x, int64_t y, int64_t width,
+sc_sdl_create_window(const char *title, int64_t x, int64_t y, int64_t width,
                      int64_t height, int64_t flags);
 
+struct sc_size
+sc_sdl_get_window_size(SDL_Window *window);
+
+void
+sc_sdl_set_window_size(SDL_Window *window, struct sc_size size);
+
+struct sc_size
+sc_sdl_get_window_size_in_pixels(SDL_Window *window);
+
+struct sc_point
+sc_sdl_get_window_position(SDL_Window *window);
+
+void
+sc_sdl_set_window_position(SDL_Window *window, struct sc_point point);
+
+void
+sc_sdl_show_window(SDL_Window *window);
+
+void
+sc_sdl_hide_window(SDL_Window *window);
+
+void
+sc_sdl_restore_window(SDL_Window *window);
+
+bool
+sc_sdl_render_clear(SDL_Renderer *renderer);
+
+void
+sc_sdl_render_present(SDL_Renderer *renderer);
+
 #endif

app/src/v4l2_sink.c

@@ -146,11 +146,9 @@ run_v4l2_sink(void *data) {
 }
 
 static bool
-sc_v4l2_sink_open(struct sc_v4l2_sink *vs, const AVCodecContext *ctx,
-                  const struct sc_stream_session *session) {
+sc_v4l2_sink_open(struct sc_v4l2_sink *vs, const AVCodecContext *ctx) {
     assert(ctx->pix_fmt == AV_PIX_FMT_YUV420P);
     (void) ctx;
-    (void) session;
 
     bool ok = sc_frame_buffer_init(&vs->fb);
     if (!ok) {
@@ -328,10 +326,9 @@ sc_v4l2_sink_push(struct sc_v4l2_sink *vs, const AVFrame *frame) {
 }
 
 static bool
-sc_v4l2_frame_sink_open(struct sc_frame_sink *sink, const AVCodecContext *ctx,
-                        const struct sc_stream_session *session) {
+sc_v4l2_frame_sink_open(struct sc_frame_sink *sink, const AVCodecContext *ctx) {
     struct sc_v4l2_sink *vs = DOWNCAST(sink);
-    return sc_v4l2_sink_open(vs, ctx, session);
+    return sc_v4l2_sink_open(vs, ctx);
 }
 
 static void

doc/develop.md

@@ -409,11 +409,12 @@ with any client which uses the same protocol.
 
 For simplicity, some [server-specific options] have been added to produce raw
 streams easily:
- - `send_device_meta=false`: disable device metadata (in practice, the device
+ - `send_device_meta=false`: disable the device metata (in practice, the device
    name) sent on the _first_ socket
  - `send_frame_meta=false`: disable the 12-byte header for each packet
  - `send_dummy_byte`: disable the dummy byte sent on forward connections
- - `send_stream_meta`: disable codec and video size metadata
+ - `send_codec_meta`: disable the codec information (and initial device size for
+   video)
  - `raw_stream`: disable all the above
 
 [server-specific options]: https://github.com/Genymobile/scrcpy/blob/a3cdf1a6b86ea22786e1f7d09b9c202feabc6949/server/src/main/java/com/genymobile/scrcpy/Options.java#L309-L329

server/src/main/java/com/genymobile/scrcpy/Options.java

@@ -78,7 +78,7 @@ public class Options {
     private boolean sendDeviceMeta = true; // send device name and size
     private boolean sendFrameMeta = true; // send PTS so that the client may record properly
     private boolean sendDummyByte = true; // write a byte on start to detect connection issues
-    private boolean sendStreamMeta = true; // write the stream metadata (codec and session)
+    private boolean sendCodecMeta = true; // write the codec metadata before the stream
 
     public Ln.Level getLogLevel() {
         return logLevel;
@@ -284,8 +284,8 @@ public class Options {
         return sendDummyByte;
     }
 
-    public boolean getSendStreamMeta() {
-        return sendStreamMeta;
+    public boolean getSendCodecMeta() {
+        return sendCodecMeta;
     }
 
     @SuppressWarnings("MethodLength")
@@ -500,8 +500,8 @@ public class Options {
                 case "send_dummy_byte":
                     options.sendDummyByte = Boolean.parseBoolean(value);
                     break;
-                case "send_stream_meta":
-                    options.sendStreamMeta = Boolean.parseBoolean(value);
+                case "send_codec_meta":
+                    options.sendCodecMeta = Boolean.parseBoolean(value);
                     break;
                 case "raw_stream":
                     boolean rawStream = Boolean.parseBoolean(value);
@@ -509,7 +509,7 @@ public class Options {
                         options.sendDeviceMeta = false;
                         options.sendFrameMeta = false;
                         options.sendDummyByte = false;
-                        options.sendStreamMeta = false;
+                        options.sendCodecMeta = false;
                     }
                     break;
                 default:

server/src/main/java/com/genymobile/scrcpy/Server.java

@@ -125,7 +125,7 @@ public final class Server {
                     audioCapture = new AudioPlaybackCapture(options.getAudioDup());
                 }
 
-                Streamer audioStreamer = new Streamer(connection.getAudioFd(), audioCodec, options.getSendStreamMeta(), options.getSendFrameMeta());
+                Streamer audioStreamer = new Streamer(connection.getAudioFd(), audioCodec, options.getSendCodecMeta(), options.getSendFrameMeta());
                 AsyncProcessor audioRecorder;
                 if (audioCodec == AudioCodec.RAW) {
                     audioRecorder = new AudioRawRecorder(audioCapture, audioStreamer);
@@ -136,7 +136,7 @@ public final class Server {
             }
 
             if (video) {
-                Streamer videoStreamer = new Streamer(connection.getVideoFd(), options.getVideoCodec(), options.getSendStreamMeta(),
+                Streamer videoStreamer = new Streamer(connection.getVideoFd(), options.getVideoCodec(), options.getSendCodecMeta(),
                         options.getSendFrameMeta());
                 SurfaceCapture surfaceCapture;
                 if (options.getVideoSource() == VideoSource.DISPLAY) {

server/src/main/java/com/genymobile/scrcpy/device/Streamer.java

@@ -14,13 +14,12 @@ import java.util.Arrays;
 
 public final class Streamer {
 
-    private static final long PACKET_FLAG_SESSION = 1L << 63;
-    private static final long PACKET_FLAG_CONFIG = 1L << 62;
-    private static final long PACKET_FLAG_KEY_FRAME = 1L << 61;
+    private static final long PACKET_FLAG_CONFIG = 1L << 63;
+    private static final long PACKET_FLAG_KEY_FRAME = 1L << 62;
 
     private final FileDescriptor fd;
     private final Codec codec;
-    private final boolean sendStreamMeta;
+    private final boolean sendCodecMeta;
     private final boolean sendFrameMeta;
 
     private final ByteBuffer headerBuffer = ByteBuffer.allocate(12);
@@ -28,7 +27,7 @@ public final class Streamer {
     public Streamer(FileDescriptor fd, Codec codec, boolean sendCodecMeta, boolean sendFrameMeta) {
         this.fd = fd;
         this.codec = codec;
-        this.sendStreamMeta = sendCodecMeta;
+        this.sendCodecMeta = sendCodecMeta;
         this.sendFrameMeta = sendFrameMeta;
     }
 
@@ -37,7 +36,7 @@ public final class Streamer {
     }
 
     public void writeAudioHeader() throws IOException {
-        if (sendStreamMeta) {
+        if (sendCodecMeta) {
             ByteBuffer buffer = ByteBuffer.allocate(4);
             buffer.putInt(codec.getId());
             buffer.flip();
@@ -45,10 +44,12 @@ public final class Streamer {
         }
     }
 
-    public void writeVideoHeader() throws IOException {
-        if (sendStreamMeta) {
-            ByteBuffer buffer = ByteBuffer.allocate(4);
+    public void writeVideoHeader(Size videoSize) throws IOException {
+        if (sendCodecMeta) {
+            ByteBuffer buffer = ByteBuffer.allocate(12);
             buffer.putInt(codec.getId());
+            buffer.putInt(videoSize.getWidth());
+            buffer.putInt(videoSize.getHeight());
             buffer.flip();
             IO.writeFully(fd, buffer);
         }
@@ -88,18 +89,6 @@ public final class Streamer {
         writePacket(codecBuffer, pts, config, keyFrame);
     }
 
-    public void writeSessionMeta(int width, int height) throws IOException {
-        if (sendStreamMeta) {
-            headerBuffer.clear();
-
-            headerBuffer.putInt((int) (PACKET_FLAG_SESSION >> 32)); // Set the first bit to 1
-            headerBuffer.putInt(width);
-            headerBuffer.putInt(height);
-            headerBuffer.flip();
-            IO.writeFully(fd, headerBuffer);
-        }
-    }
-
     private void writeFrameMeta(FileDescriptor fd, int packetSize, long pts, boolean config, boolean keyFrame) throws IOException {
         headerBuffer.clear();
 

server/src/main/java/com/genymobile/scrcpy/video/SurfaceEncoder.java

@@ -71,13 +71,16 @@ public class SurfaceEncoder implements AsyncProcessor {
 
         try {
             boolean alive;
-
-            streamer.writeVideoHeader();
+            boolean headerWritten = false;
 
             do {
                 reset.consumeReset(); // If a capture reset was requested, it is implicitly fulfilled
                 capture.prepare();
                 Size size = capture.getSize();
+                if (!headerWritten) {
+                    streamer.writeVideoHeader(size);
+                    headerWritten = true;
+                }
 
                 format.setInteger(MediaFormat.KEY_WIDTH, size.getWidth());
                 format.setInteger(MediaFormat.KEY_HEIGHT, size.getHeight());
@@ -104,7 +107,6 @@ public class SurfaceEncoder implements AsyncProcessor {
                         boolean resetRequested = reset.consumeReset();
                         if (!resetRequested) {
                             // If a reset is requested during encode(), it will interrupt the encoding by an EOS
-                            streamer.writeSessionMeta(size.getWidth(), size.getHeight());
                             encode(mediaCodec, streamer);
                         }
                         // The capture might have been closed internally (for example if the camera is disconnected)