[FFmpeg-user] H.264 single access unit decoding

[Etienne Buira]

On Tue, Mar 29, 2011 at 12:34:11PM +0000, Robert Sitan wrote:
> 
> Dear experts,
> 
> When trying to decode a single I picture preceded by an Access Unit Delimiter and a SPS, a PPS and a SEI, ffmpeg outputs the following error message:
> 
> rob at rob$ ffmpeg -i Ipicture_single.264 Ipicture_single_ffmpeg.yuv
> FFmpeg version SVN-r25478-snapshot, Copyright (c) 2000-2010 the FFmpeg developers
>   built on Oct 15 2010 14:27:37 with gcc 4.4.3
>   configuration: 
>   libavutil     50.32. 3 / 50.32. 3
>   libavcore      0. 9. 1 /  0. 9. 1
>   libavcodec    52.92. 0 / 52.92. 0
>   libavformat   52.82. 0 / 52.82. 0
>   libavdevice   52. 2. 2 / 52. 2. 2
>   libavfilter    1.51. 1 /  1.51. 1
>   libswscale     0.12. 0 /  0.12. 0
> [NULL @ 0x91a0470] Format detected only with low score of 24, misdetection possible!

Hi.

Try with ffmpeg -f h264 -i input.264 ...

> [mp3 @ 0x91a2d50] Header missing                                                                                                                                                                                                             
>     Last message repeated 14 times                                                                                                                                                                                                           
> [mp3 @ 0x91a0470] Could not find codec parameters (Audio: mp1, 0 channels, s16)
> [mp3 @ 0x91a0470] Estimating duration from bitrate, this may be inaccurate                                                                                                                                                                   
> /home/rob/Ipicture_single.264: could not find codec parameters
> 
> The same .264 image can be decoded with the JM reference decoder without any error. You can get the .264 bitstream here: http://www.megaupload.com/?d=WA8BD5VD
> 
> However, when decoding the whole GOP, ffmpeg seems to work ok. Are there any restrictions on single access unit decoding with ffmpeg?
> 
> Thanks.
> 
> Rob.