[FFmpeg-devel] reported length of a clip

[Marcus Engene]

Hi,

Looking in libavformat/utils.c:av_update_stream_timings() i notice that 
the length of the clip is the longest of the streams.

If I have a clip whose audio stream is longer than the video stream, the 
length of the audio stream is reported as a consequence of this.

To me, in this context, the length of the video stream in the important 
length, but in an example clip this is not to be read anywhere:

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '000117245.mov':
  Duration: 00:00:09.9, start: 0.000000, bitrate: 168686 kb/s
    Stream #0.0(eng): Video: mjpegb, yuvj422p, 1920x1080 [PAR 0:1 DAR 
0:1], 29.97 tb(r)
    Stream #0.1(eng): Audio: pcm_s16le, 48000 Hz, stereo, 1536 kb/s
    Stream #0.2(eng): Data: tmcd / 0x64636D74

I guess the max length value makes sense on Input #0, but would it be 
possible to present the individual lengths of the streams somehow?

mencoder with verbose output reports the following for the clip 
mentioned above:

MEncoder 1.0rc1-3.4.2 (C) 2000-2006 MPlayer Team
CPU: Genuine Intel(R) CPU           T2300  @ 1.66GHz (Family: 6, Model: 
14, Stepping: 8)
CPUflags: Type: 6 MMX: 1 MMX2: 1 3DNow: 0 3DNow2: 0 SSE: 0 SSE2: 0
Compiled with runtime CPU detection.
init_freetype
get_path('font/font.desc') -> 
'C:\cygwin\home\ehsmeng/mplayer/font/font.desc'
font: can't open file: C:\cygwin\home\ehsmeng/mplayer/font/font.desc
font: can't open file: /usr/local/share/mplayer/font/font.desc
Using MMX (with tiny bit MMX2) Optimized OnScreenDisplay
WINSOCK2 init: 0
[file] File size is 210418198 bytes
STREAM: [file] 000117245.mov
STREAM: Description: File
STREAM: Author: Albeu
STREAM: Comment: based on the code from ??? (probably Arpi)
success: format: 0  data: 0x0 - 0xc8aba16
Checking for YUV4MPEG2
ASF_check: not ASF guid!
Checking for NuppelVideo
Checking for REAL
Checking for SMJPEG
Searching demuxer type for filename 000117245.mov ext: .mov
Trying demuxer 7 based on filename extension
Checking for MOV
ISO: File Type Major Brand: Original QuickTime
ISO: File Type Minor Version: 537199360
ISO: File Type Compatible Brand #0: qt 
ISO: File Type Compatible Brand #1:
ISO: File Type Compatible Brand #2:
ISO: File Type Compatible Brand #3:
MOV: 'WIDE' chunk found!
MOV: Movie DATA found!
MOV: Movie DATA found!
MOV: 'WIDE' chunk found!
MOV: Movie DATA found!
MOV: Movie header found!
Quicktime/MOV file format detected.
MOV: Movie header (100 bytes): tscale=30000  dur=233233
--------------
MOV: Track #0:
MOV:  Track header!
tkhd len=84 ver=0 flags=0x0 id=1 dur=233233 lay=0 vol=0
MOV: unknown chunk: load 16
MOV:  Edit atom!
MOV:   Edit list table (1 entries) (ver:0,flags:0)
MOV:     entry#0: duration: 233233  start time: 0  speed: 1.0x
MOV: unknown chunk: tref 12
MOV:  Media stream!
MOV:   Media header!
MOV:   Handler header: mhlr/vide (appl) Apple Video Media Handler
MOV:   Media info!
MOV:    Video header!
MOV:    Handler header: dhlr/alis (appl) Apple Alias Data Handler
MOV: unknown chunk: dinf 28
MOV:    Sample info!
MOV:     Description list! (cnt:1)
MOV:      desc #0: mjpb  (96 bytes)
MOV:     Sample duration table! (1 blocks)
MOV:     Sample->Chunk mapping table!  (1 blocks) (ver:0,flags:0)
MOV:     Sample size table! (entries=233 ss=0) (ver:0,flags:0)
MOV:     Chunk offset table! (233 chunks)
MOV track #0: 233 chunks, 233 samples
pts=233233  scale=30000  time=7.774
EL#0: pts=0  1st_sample=0  frames=233 (7.774s)  pts_offs=0
==> Found video stream: 0
MOV: Found unsupported Field-Handling movie atom (10)!
MOV: Found unsupported Gamma-Correction movie atom (12)!
Image size: 1920 x 1080 (24 bpp)
Display size: 1920 x 1080
Fourcc: mjpb  Codec: 'Motion JPEG B'
--------------
MOV: Track #1:
MOV:  Track header!
tkhd len=84 ver=0 flags=0x0 id=2 dur=233233 lay=0 vol=256
MOV:  Edit atom!
MOV:   Edit list table (1 entries) (ver:0,flags:0)
MOV:     entry#0: duration: 233233  start time: 0  speed: 1.0x
MOV: unknown chunk: tref 12
MOV:  Media stream!
MOV:   Media header!
MOV:   Handler header: mhlr/soun (appl) Apple Sound Media Handler
MOV:   Media info!
MOV:    Sound header!
MOV:    Handler header: dhlr/alis (appl) Apple Alias Data Handler
MOV: unknown chunk: dinf 28
MOV:    Sample info!
MOV:     Description list! (cnt:1)
MOV:      desc #0: sowt  (100 bytes)
MOV:     Sample duration table! (1 blocks)
MOV:     Sample->Chunk mapping table!  (2 blocks) (ver:0,flags:0)
MOV:     Sample size table! (entries=478998 ss=1) (ver:0,flags:0)
MOV:     Chunk offset table! (11 chunks)
MOV track #1: 11 chunks, 0 samples
pts=478998  scale=48000  time=9.979
==> Found audio stream: 1
Audio bits: 16  chans: 2  rate: 48000
Audio header: samp/pack=1 bytes/pack=2 bytes/frame=4 bytes/samp=2 
Audio extra header: len=64  fcc=0x6368616E
MOV: Found unknown audio atom Fourcc: sowt
--------------
MOV: Track #2:
MOV:  Track header!
tkhd len=84 ver=0 flags=0x0 id=3 dur=233233 lay=0 vol=0
MOV:  Edit atom!
MOV:   Edit list table (1 entries) (ver:0,flags:0)
MOV:     entry#0: duration: 233233  start time: 0  speed: 1.0x
MOV:  Media stream!
MOV:   Media header!
MOV:   Handler header: mhlr/tmcd (appl) Time Code Media Handler
MOV:   Media info!
MOV:    Generic header!
MOV:    Handler header: dhlr/alis (appl) Apple Alias Data Handler
MOV: unknown chunk: dinf 28
MOV:    Sample info!
MOV:     Description list! (cnt:1)
MOV:      desc #0: tmcd  (18 bytes)
MOV:     Sample duration table! (1 blocks)
MOV:     Sample->Chunk mapping table!  (1 blocks) (ver:0,flags:0)
MOV:     Sample size table! (entries=1 ss=4) (ver:0,flags:0)
MOV:     Chunk offset table! (1 chunks)
MOV track #2: 1 chunks, 0 samples
pts=233233  scale=30000  time=7.774
EL#0: pts=0  1st_sample=0  frames=1 (7.774s)  pts_offs=0
Generic track - not completely understood! (id: 2)
--------------
Quicktime Clip Info:
MOV: longest streams: A: #1 (11 samples)  V: #0 (233 samples)
VIDEO:  [mjpb]  1920x1080  24bpp  29.970 fps    0.0 kbps ( 0.0 kbyte/s)
[V] filefmt:7  fourcc:0x62706A6D  size:1920x1080  fps:29.97  ftime:=0.0334

Exiting...