On 07/08/17 20:24, Jorge Ramirez wrote: > On 08/03/2017 01:53 AM, Mark Thompson wrote: >>> + default: >>> + return 0; >>> + } >>> + >>> + SET_V4L_EXT_CTRL(value, qmin, avctx->qmin, "minimum video quantizer >>> scale"); >>> + SET_V4L_EXT_CTRL(value, qmax, avctx->qmax, "maximum video quantizer >>> scale"); >>> + >>> + return 0; >>> +} >> This doesn't set extradata - you need to extract the codec global headers >> (such as H.264 SPS and PPS) at init time to be able to write correct files >> for some codecs (such as H.264) with muxers requiring global headers (such >> as MP4). It kindof works without it, but the files created will not conform >> and will not be usable on some players. >> > ah that might explain some things (when I play back the encoded video the > quality is pretty lousy) > is there already some code I can use as a reference? I might be out of my > depth here so any help will be more than welcome
Methods used by other codecs to extract the headers: Something to call directly to get them: * x264_encoder_headers in libx264: <http://git.videolan.org/?p=x264.git;a=blob;f=x264.h#l895>. * nvEncGetSequenceParams in nvenc: <http://git.videolan.org/?p=ffmpeg.git;a=blob;f=libavcodec/nvenc.c;h=f79b9a502e33c66e62513c56e54e9cec041e9d45;hb=HEAD#l1282>. They appear on the front of the stream and can be read from there at init time: * OMX_BUFFERFLAG_CODECCONFIG in OpenMAX IL: <http://git.videolan.org/?p=ffmpeg.git;a=blob;f=libavcodec/omx.c;h=19b4f33836b68fabe7be921ca959c619dd28e535;hb=HEAD#l685>. Know the answer magically in advance (probably not applicable here): * VAAPI makes the user write their own headers, so we can just write those to the extradata directly as well: <http://git.videolan.org/?p=ffmpeg.git;a=blob;f=libavcodec/vaapi_encode.c;h=2de5f76cabf329c92272627ee13ab3c8689806d3;hb=HEAD#l1471>. _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
