[Theora] help - Theora/Vorbis/Ogg, ogmmerge and ffmpeg2theora

[Ian Kirk]

Hi,

I'm probably being fairly stupid. But I did the following, starting with
the following two files:

  # tcprobe -i vts_01.m2v
  [tcprobe] MPEG elementary stream (ES)
  [tcprobe] summary for vts_01.m2v, (*) = not default, 0 = not detected
  import frame size: -g 720x576 [720x576]
       aspect ratio: 16:9 (*)
         frame rate: -f 25.000 [25.000] frc=3

  # tcprobe -i vts_01.m2a
  [tcprobe] AC3 stream
  [tcprobe] summary for vts_01.m2a, (*) = not default, 0 = not detected
        audio track: -a 0 [0] -e 48000,16,2 [48000,16,2] -n 0x2000
         bitrate=192 kbps

Then proceeded to convert them into Vorbis/Theora/Ogg files.

  transcode -i vts_01.m2a -y ogg -o vts_01.m2a.ogg

which gave:

  # ogminfo vts_01.m2a.ogg
  (ogminfo.c) (a1/serial 1677883185) Vorbis audio (channels 2 rate 48000)

I also did:

  ffmpeg2theora -x 720 -y 576 vts_01.m2v

which gave:

  # ogminfo vts_01.m2v.ogg
  (ogminfo.c) OGG stream 1 is of an unknown type (bad header?)

and also gave me:

  # ogmmerge -v -o test.ogg vts_01.m2a.ogg vts_01.m2v.ogg
  Using OGG/OGM demultiplexer for vts_01.m2a.ogg.
  +-> Using Vorbis audio output module for stream 1.
  Using OGG/OGM demultiplexer for vts_01.m2v.ogg.
  0.000000 (timestamp) written header page for vts_01.m2a.ogg
  Error: the reader for vts_01.m2v.ogg did not produce a header page.

The vts_01.m2v.ogg file plays fine under VLC. It also appears to have Ogg
headers:

  # hexdump -C /data/mpeg4/VIDEO_TS/vts_01.m2v.ogg | head
  000  4f 67 67 53 00 02 00 00  00 00 00 00 00 00 e7 e6  |OggS............|
  010  77 1a 00 00 00 00 3d 33  c0 4f 01 2a 80 74 68 65  |w.....=3.O.*.the|
  020  6f 72 61 03 02 00 00 2d  00 24 00 02 d0 00 02 40  |ora....-.$.....@|
  030  00 00 00 00 61 c1 00 00  03 e9 00 00 00 00 00 00  |....a...........|
  040  02 00 00 00 7c c0 4f 67  67 53 00 00 00 00 00 00  |....|.OggS......|
  050  00 00 00 00 e7 e6 77 1a  01 00 00 00 f7 d8 b0 29  |......w........)|
  060  0c 50 ff ff ff ff ff ff  ff ff ff ff 57 81 74 68  |.P..........W.th|
  070  65 6f 72 61 23 00 00 00  58 69 70 68 2e 4f 72 67  |eora#...Xiph.Org|
  080  20 6c 69 62 54 68 65 6f  72 61 20 49 20 32 30 30  | libTheora I 200|
  090  34 30 33 31 37 20 33 20  32 20 30 01 00 00 00 1a  |40317 3 2 0.....|

My question (i'm getting to one) is :-

Assuming I've encoded the two streams/files correctly, how can I mux them
together to have a Vorbis/Theora Ogg file ?

Regards,
Ian

--
s/w versions:

libvorbis-1.0.1
vorbis-tools-1.0.1
libogg-1.1
ogmtools-1.4.1
libtheora-1.0-0.alpha3.4
ffmpeg2theora-0.12