games/vcmi
1
0
Fork 0
mirror of https://github.com/vcmi/vcmi.git synced 2025-10-31 00:07:39 +02:00
Code Issues Releases Activity

Clarified & simplified ffmpeg decoding loop

Browse Source
This commit is contained in:
Ivan Savenko
2024-06-01 11:48:54 +00:00
parent b8beb4fb13
commit d462937572
1 changed files with 25 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files

43
client/media/CVideoHandler.cpp
View File

@@ -219,22 +219,21 @@ void CVideoInstance::prepareOutput(bool scaleToScreenSize, bool useTextureOutput
void FFMpegStream::decodeNextFrame()
{
AVPacket packet;
for(;;)
{
int rc = avcodec_receive_frame(codecContext, frame);
if(rc == AVERROR(EAGAIN))
break;
if(rc < 0)
throwFFmpegError(rc);
int rc = avcodec_receive_frame(codecContext, frame);
// frame extracted - data that was sent to codecContext before was sufficient
if (rc == 0)
return;
}
// returning AVERROR(EAGAIN) is legal - this indicates that codec requires more data from input stream to decode next frame
if(rc != AVERROR(EAGAIN))
throwFFmpegError(rc);
for(;;)
{
AVPacket packet;
// codecContext does not have enough input data - read next packet from input stream
int ret = av_read_frame(formatContext, &packet);
if(ret < 0)
{
@@ -248,25 +247,33 @@ void FFMpegStream::decodeNextFrame()
throwFFmpegError(ret);
}
// Is this a packet from the video stream?
// Is this a packet from the stream that needs decoding?
if(packet.stream_index == streamIndex)
{
// Decode video frame
// Decode read packet
// Note: this method may return AVERROR(EAGAIN). However this should never happen with ffmpeg API
// since there is guaranteed call to avcodec_receive_frame and ffmpeg API promises that *both* of these methods will never return AVERROR(EAGAIN).
int rc = avcodec_send_packet(codecContext, &packet);
if(rc < 0 && rc != AVERROR(EAGAIN))
if(rc < 0)
throwFFmpegError(rc);
rc = avcodec_receive_frame(codecContext, frame);
if(rc == AVERROR(EAGAIN))
{
// still need more data - read next packet
av_packet_unref(&packet);
continue;
}
if(rc < 0)
else if(rc < 0)
{
throwFFmpegError(rc);
av_packet_unref(&packet);
return;
}
else
{
// read succesful. Exit the loop
av_packet_unref(&packet);
return;
}
}
av_packet_unref(&packet);
}