[FFmpeg-user] Invalid SampleDelta in STTS

[Julien Carrier]

Hello,

I use ffmpeg to encode video files in order to use in HTML5 video tag. My
input files are .mp4 files in h264 exported from Adobe Premiere CS5 and I
want to create two output files, one in h264 - aac with higher compression
in baseline profile and one in webm VP8 - vorbis.

For some input files, I've got this warning from ffmpeg:
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x178f3a0] Invalid SampleDelta in STTS -31999.
It does not prevent me from encoding the files but I would like to ask you
what does it mean and if I should care and do something about it.

I paste here the ffmpeg log for a webm compression:

*******
ffmpeg version N-38686-gd07de6d Copyright (c) 2000-2012 the FFmpeg
developers
  built on Mar  9 2012 17:08:40 with gcc 4.4.3
  configuration: --enable-libmp3lame --enable-libxvid --enable-libvorbis
--enable-gpl --enable-libfaac --enable-libtheora --enable-zlib
--disable-shared --enable-libx264 --enable-libdirac --enable-nonfree
--enable-version3 --enable-libschroedinger --enable-avfilter
--enable-libspeex --enable-libopenjpeg --enable-libgsm --enable-postproc
--enable-pthreads --enable-libopencore-amrnb --enable-libopencore-amrwb
--enable-ffplay --enable-pthreads --prefix=/usr/local --enable-x11grab
--enable-runtime-cpudetect --enable-bzlib --enable-libdc1394 --enable-libvpx
  libavutil      51. 42.100 / 51. 42.100
  libavcodec     54. 10.100 / 54. 10.100
  libavformat    54.  2.100 / 54.  2.100
  libavdevice    53.  4.100 / 53.  4.100
  libavfilter     2. 63.100 /  2. 63.100
  libswscale      2.  1.100 /  2.  1.100
  libswresample   0.  7.100 /  0.  7.100
  libpostproc    52.  0.100 / 52.  0.100
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x1d153a0] Invalid SampleDelta in STTS -31999
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'inputVideo.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: mp42mp41
    creation_time   : 2012-12-14 15:25:22
  Duration: 00:01:31.05, start: 0.000000, bitrate: 14312 kb/s
    Stream #0:0(eng): Video: h264 (Main) (avc1 / 0x31637661), yuv420p,
800x450 [SAR 1:1 DAR 16:9], 14005 kb/s, 25.01 fps, 25 tbr, 25k tbn, 50 tbc
    Metadata:
      creation_time   : 2012-12-14 15:25:22
      handler_name    : Mainconcept MP4 Video Media Handler
    Stream #0:1(eng): Audio: aac (mp4a / 0x6134706D), 48000 Hz, stereo,
s16, 317 kb/s
    Metadata:
      creation_time   : 2012-12-14 15:25:22
      handler_name    : Mainconcept MP4 Sound Media Handler
[buffer @ 0x1d152c0] w:800 h:450 pixfmt:yuv420p tb:1/1000000 sar:1/1
sws_param:
Incompatible sample format 's16' for codec 'libvorbis', auto-selecting
format 'flt'
[libvpx @ 0x1d280e0] v0.9.7-p1
[libvpx @ 0x1d280e0] --enable-pic --enable-shared --disable-install-bins
--disable-install-srcs --target=x86_64-linux-gcc
Output #0, webm, to '/home/juju/videos/outputVid.webm':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: mp42mp41
    creation_time   : 2012-12-14 15:25:22
    encoder         : Lavf54.2.100
    Stream #0:0(eng): Video: vp8, yuv420p, 800x450 [SAR 1:1 DAR 16:9],
q=10-42, 300 kb/s, 1k tbn, 25 tbc
    Metadata:
      creation_time   : 2012-12-14 15:25:22
      handler_name    : Mainconcept MP4 Video Media Handler
    Stream #0:1(eng): Audio: vorbis, 48000 Hz, 1 channels, flt, 96 kb/s
    Metadata:
      creation_time   : 2012-12-14 15:25:22
      handler_name    : Mainconcept MP4 Sound Media Handler
Stream mapping:
  Stream #0:0 -> #0:0 (h264 -> libvpx)
  Stream #0:1 -> #0:1 (aac -> libvorbis)
Press [q] to stop, [?] for help
frame= 2275 fps= 11 q=0.0 Lsize=    3989kB time=00:01:31.04 bitrate=
358.9kbits/s
video:2870kB audio:1067kB global headers:4kB muxing overhead 1.219887%
********


Thank you very much for your advice.

Julien