scrcpy/app/src/decoder.c
Romain Vimont 8595862005 Use explicit output parameter for skipped frame
The function video_buffer_offer_decoded_frame() returned a bool to
indicate whether the previous frame had been consumed.

This was confusing, because we could expect the returned bool report
whether the action succeeded.

Make the semantic explicit by using an output parameter.

Also revert the flag (report if the frame has been skipped instead of
consumed) to avoid confusion for the first frame (the previous is
neither skipped nor consumed because there is no previous frame).
2019-03-03 00:35:20 +01:00

103 lines
2.8 KiB
C

#include "decoder.h"
#include <libavformat/avformat.h>
#include <libavutil/time.h>
#include <SDL2/SDL_assert.h>
#include <SDL2/SDL_events.h>
#include <SDL2/SDL_mutex.h>
#include <SDL2/SDL_thread.h>
#include <unistd.h>
#include "compat.h"
#include "config.h"
#include "buffer_util.h"
#include "events.h"
#include "lock_util.h"
#include "log.h"
#include "recorder.h"
#include "video_buffer.h"
// set the decoded frame as ready for rendering, and notify
static void
push_frame(struct decoder *decoder) {
bool previous_frame_skipped;
video_buffer_offer_decoded_frame(decoder->video_buffer,
&previous_frame_skipped);
if (previous_frame_skipped) {
// the previous EVENT_NEW_FRAME will consume this frame
return;
}
static SDL_Event new_frame_event = {
.type = EVENT_NEW_FRAME,
};
SDL_PushEvent(&new_frame_event);
}
void
decoder_init(struct decoder *decoder, struct video_buffer *vb) {
decoder->video_buffer = vb;
}
bool
decoder_open(struct decoder *decoder, AVCodec *codec) {
decoder->codec_ctx = avcodec_alloc_context3(codec);
if (!decoder->codec_ctx) {
LOGC("Could not allocate decoder context");
return false;
}
if (avcodec_open2(decoder->codec_ctx, codec, NULL) < 0) {
LOGE("Could not open codec");
avcodec_free_context(&decoder->codec_ctx);
return false;
}
return true;
}
void
decoder_close(struct decoder *decoder) {
avcodec_close(decoder->codec_ctx);
avcodec_free_context(&decoder->codec_ctx);
}
bool
decoder_push(struct decoder *decoder, AVPacket *packet) {
// the new decoding/encoding API has been introduced by:
// <http://git.videolan.org/?p=ffmpeg.git;a=commitdiff;h=7fc329e2dd6226dfecaa4a1d7adf353bf2773726>
#ifdef SCRCPY_LAVF_HAS_NEW_ENCODING_DECODING_API
int ret;
if ((ret = avcodec_send_packet(decoder->codec_ctx, packet)) < 0) {
LOGE("Could not send video packet: %d", ret);
return false;
}
ret = avcodec_receive_frame(decoder->codec_ctx,
decoder->video_buffer->decoding_frame);
if (!ret) {
// a frame was received
push_frame(decoder);
} else if (ret != AVERROR(EAGAIN)) {
LOGE("Could not receive video frame: %d", ret);
return false;
}
#else
int got_picture;
int len = avcodec_decode_video2(decoder->codec_ctx,
decoder->video_buffer->decoding_frame,
&got_picture,
packet);
if (len < 0) {
LOGE("Could not decode video packet: %d", len);
return false;
}
if (got_picture) {
push_frame(decoder);
}
#endif
return true;
}
void
decoder_interrupt(struct decoder *decoder) {
video_buffer_interrupt(decoder->video_buffer);
}