[FFmpeg-devel] lowres flag question

Jai Menon jmenon86
Tue May 26 08:27:04 CEST 2009

On Mon, May 25, 2009 at 3:28 PM, Jai Menon <jmenon86 at gmail.com> wrote:
> Hi,
> I'm trying to fix issue 1097 and something seems weird about the
> lowres flag. In av_find_stream_info, try_decode_frame is called to
> discover codec parameters but the lowres flag is not passed through
> (even though "-lowres 1" is passed on the command line). Consequently,
> width and height are set to the actual values instead of
> w>>lowres,h>>lowres by avcodec_set_dimensions.
> The problem is that even though subsequent calls to decode_frame
> (through avcodec_decode_video2) compute width and height correctly,
> these are not being set correctly in the AVCodecContext. That is, the
> output image that lavc expects is still w,h.
> Is this a known bug/feature?
> Jai

I'm not sure if what I wrote was clear, but I think this is the reason
why mpeg1video, mpeg2video and some other codecs crash when -lowres is



More information about the ffmpeg-devel mailing list