FFmpeg old version, We initialize AVCodecContext often use the follow code.
But, in the FFmpeg new version, the streams->codec
code be declared attribute_deprecated
, it is suggest not to use the follow code.
AVCodecContext * pCodecCtx = pFormatCtx->streams[videoIndex]->codec;
AVCodec * pCodec = avcodec_find_decoder(pCodecCtx->codec_id);
How should we do?
The avcodec_open2
method’s document advice to use avcodec_alloc_context3()
method.
The document is introduced in detail how should we do.
But, it missing a method. It is avcodec_parameters_to_context()
method.
AVCodec *pCodec = avcodec_find_decoder(pFormatCtx->streams[videoIndex]->codecpar->codec_id);
AVCodecContext *pCodecCtx = avcodec_alloc_context3(pCodec);
avcodec_parameters_to_context(pCodecCtx, pFormatCtx->streams[videoIndex]->codecpar);
if (avcodec_open2(pCodecCtx, pCodec, NULL) < 0) {
printf("Could not open codec.\n");
return -1;
}