[Ffmpeg-devel] Underflows and overflows with 720p h.264 video

[Michael Niedermayer]

Hi

On Fri, Nov 03, 2006 at 01:47:24AM -0800, Aaron Williams wrote:
> Hi,
> 
> I have a 1280x720 h.264 wmv file I am trying to shrink down to 720x480
> and am running into a lot of problems with ffmpeg.  I am running ffmpeg
> rev 6869 and x264 rev 598.
> 
[...]
> ffmpeg -i t_whiteknightstory_tgs06_h264.wmv -s 720x480 -vcodec h264
> -acodec copy -b 1500k -maxrate 2400k -bufsize 262144 -flags
> +trell+qpel+loop -aspect 16:9 -pass 1 whitenightstory.wmv
> FFmpeg version SVN-r6869, Copyright (c) 2000-2006 Fabrice Bellard, et al.
>   configuration:  --enable-libogg --enable-vorbis --enable-faad
> --enable-faac --enable-xvid --enable-x264 --enable-a52 --enable-dts
> --enable-dc1394 --enable-gpl --enable-mp3lame --enable-swscaler
> --enable-pp --enable-amr_wb --enable-amr_nb --enable-amr_if2
> --cpu=athlon64 --enable-shared
>   libavutil version: 49.0.2
>   libavcodec version: 51.23.0
>   libavformat version: 50.6.0
>   built on Nov  2 2006 07:52:32, gcc: 4.1.0 (SUSE Linux)
> 
> Seems that stream 1 comes from film source: 1000.00 (1000/1) -> 29.92
> (359/12)
> Input #0, asf, from 't_whiteknightstory_tgs06_h264.wmv':
>   Duration: 00:04:48.1, start: 4.000000, bitrate: 3362 kb/s
>   Stream #0.0: Audio: wmav2, 48000 Hz, stereo, 192 kb/s
>   Stream #0.1: Video: wmv3, yuv420p, 1280x720, 29.92 fps(r)
> File 'whitenightstory.wmv' already exists. Overwrite ? [y/N] y
> Output #0, asf, to 'whitenightstory.wmv':
>   Stream #0.0: Video: h264, yuv420p, 720x480, q=2-31, pass 1, 1500 kb/s,
> 29.92 fps(c)
>   Stream #0.1: Audio: 0x0161, 48000 Hz, stereo, 192 kb/s
> Stream mapping:
>   Stream #0.1 -> #0.0
>   Stream #0.0 -> #0.1
> [h264 @ 0x2b5ec4ddf3f0]using SAR=32/27
> [h264 @ 0x2b5ec4ddf3f0]using cpu capabilities MMX MMXEXT SSE SSE2 3DNow!
> Press [q] to stop encoding
> [h264 @ 0x2b5ec4ddf3f0]OVERFLOW levelcode=4417
[...]
> [h264 @ 0x2b5ec4ddf3f0]VBV underflow (-15427 bits)te=1561.6kbits/s
> [h264 @ 0x2b5ec4ddf3f0]VBV underflow (-26029 bits)te=1574.7kbits/s

wrong mailinglist, try some x264 related one
also note that putting standand codecs in wmv will likely not work


[...]
> 
> When trying for MPEG2 instead of H.264 I get buffer underflow errors:
> 
> In this case, I used the following command:
> 
> ffmpeg -i t_whiteknightstory_tgs06_h264.wmv -vcodec mpeg2video -acodec
> mp2 -ab 192 -b 4000k -sameq -s 720x480 -maxrate 5000k -b 3000k -bufsize
> 16777216 -aspect 16:9 -pass 1 whiteknightstory.mpg
> 
> [mpeg @ 0x2ac159533fe0]buffer underflow
> (repeated many many times)

if you ask for -sameq you get same quality, this isnt possible with the
vbv constraints you set

[...]
> I might add that the original video plays just fine with MPlayer. 
> ffplay can also play it, but the audio tends to stutter.

please submit seperate bugreports for seperate issues, your mail contained
at least 4 independant ones

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

In the past you could go to a library and read, borrow or copy any book
Today you'd get arrested for mere telling someone where the library is