Rename "frames" to "video_buffer"

It better describes the purpose of the structure.
2025-12-18 22:14:20 +01:00 · 2019-03-02 15:16:55 +01:00
parent aacb09a3d6
commit fff87095d9
11 changed files with 157 additions and 155 deletions
--- a/app/src/video_buffer.c
+++ b/app/src/video_buffer.c
@@ -0,0 +1,110 @@
+#include "video_buffer.h"
+
+#include <SDL2/SDL_assert.h>
+#include <SDL2/SDL_mutex.h>
+#include <libavutil/avutil.h>
+#include <libavformat/avformat.h>
+
+#include "config.h"
+#include "lock_util.h"
+#include "log.h"
+
+SDL_bool video_buffer_init(struct video_buffer *vb) {
+    if (!(vb->decoding_frame = av_frame_alloc())) {
+        goto error_0;
+    }
+
+    if (!(vb->rendering_frame = av_frame_alloc())) {
+        goto error_1;
+    }
+
+    if (!(vb->mutex = SDL_CreateMutex())) {
+        goto error_2;
+    }
+
+#ifndef SKIP_FRAMES
+    if (!(vb->rendering_frame_consumed_cond = SDL_CreateCond())) {
+        SDL_DestroyMutex(vb->mutex);
+        goto error_2;
+    }
+    vb->stopped = SDL_FALSE;
+#endif
+
+    // there is initially no rendering frame, so consider it has already been
+    // consumed
+    vb->rendering_frame_consumed = SDL_TRUE;
+    fps_counter_init(&vb->fps_counter);
+
+    return SDL_TRUE;
+
+error_2:
+    av_frame_free(&vb->rendering_frame);
+error_1:
+    av_frame_free(&vb->decoding_frame);
+error_0:
+    return SDL_FALSE;
+}
+
+void video_buffer_destroy(struct video_buffer *vb) {
+#ifndef SKIP_FRAMES
+    SDL_DestroyCond(vb->rendering_frame_consumed_cond);
+#endif
+    SDL_DestroyMutex(vb->mutex);
+    av_frame_free(&vb->rendering_frame);
+    av_frame_free(&vb->decoding_frame);
+}
+
+static void video_buffer_swap_frames(struct video_buffer *vb) {
+    AVFrame *tmp = vb->decoding_frame;
+    vb->decoding_frame = vb->rendering_frame;
+    vb->rendering_frame = tmp;
+}
+
+SDL_bool video_buffer_offer_decoded_frame(struct video_buffer *vb) {
+    mutex_lock(vb->mutex);
+#ifndef SKIP_FRAMES
+    // if SKIP_FRAMES is disabled, then the decoder must wait for the current
+    // frame to be consumed
+    while (!vb->rendering_frame_consumed && !vb->stopped) {
+        cond_wait(vb->rendering_frame_consumed_cond, vb->mutex);
+    }
+#else
+    if (vb->fps_counter.started && !vb->rendering_frame_consumed) {
+        fps_counter_add_skipped_frame(&vb->fps_counter);
+    }
+#endif
+
+    video_buffer_swap_frames(vb);
+
+    SDL_bool previous_frame_consumed = vb->rendering_frame_consumed;
+    vb->rendering_frame_consumed = SDL_FALSE;
+
+    mutex_unlock(vb->mutex);
+    return previous_frame_consumed;
+}
+
+const AVFrame *video_buffer_consume_rendered_frame(struct video_buffer *vb) {
+    SDL_assert(!vb->rendering_frame_consumed);
+    vb->rendering_frame_consumed = SDL_TRUE;
+    if (vb->fps_counter.started) {
+        fps_counter_add_rendered_frame(&vb->fps_counter);
+    }
+#ifndef SKIP_FRAMES
+    // if SKIP_FRAMES is disabled, then notify the decoder the current frame is
+    // consumed, so that it may push a new one
+    cond_signal(vb->rendering_frame_consumed_cond);
+#endif
+    return vb->rendering_frame;
+}
+
+void video_buffer_stop(struct video_buffer *vb) {
+#ifdef SKIP_FRAMES
+    (void) vb; // unused
+#else
+    mutex_lock(vb->mutex);
+    vb->stopped = SDL_TRUE;
+    mutex_unlock(vb->mutex);
+    // wake up blocking wait
+    cond_signal(vb->rendering_frame_consumed_cond);
+#endif
+}