[FFmpeg-user] strange h264 framerate diagnostics

[Christian Ebert]

* belcampo on Monday, March 02, 2009 at 13:08:53 +0100
>> Duration: 00:04:22.04, start: 0.000000, bitrate: 30339 kb/s
> I think/believe this will be a misinterpretation by ffmpeg

Actually I think this is correct.

> What does mediainfo -f tell about test.mov and test.mp4 ?

I don't have mediainfo here, but:

$ qtinfo test.mov
Type: Quicktime
  1 audio tracks.
    2 channels, 16 bits, sample rate 48000, length 12577920 samples, compressor sowt.
    Sample format: 16 bit signed.
    Channel setup: Not available
    Language: eng
    supported.
  1 video tracks.
    720x576, depth 24
    rate 25.000000 [25:1] constant
    length 6551 frames
    compressor dvcp.
    Native colormodel:  YUV 4:2:0 planar
    Interlace mode:     Bottom field first
    Chroma placement: PAL DV
    Pixel aspect ratio: 59:54
    Timecodes available (flags: 00000000, rate: 25)
    supported.
  0 text tracks.

And QuickTime inspector says "Data Rate: 30.32 mbits/s".

And for test.mp4 (converted with a different, high quality
cmdline, I just simplified it to check that my choice of options
wasn't at fault):

$ qtinfo test-hq.mp4
Type: MP4
  1 audio tracks.
    2 channels, 16 bits, sample rate 32000, length 8387584 samples, compressor mp4a.
    Sample format: Floating point.
    Channel setup: Front Left, Front Right
    Language: und
    supported.
  1 video tracks.
    384x288, depth 24
    rate 25.000000 [25:1] constant
    length 6551 frames
    compressor avc1.
    Native colormodel:  YUV 4:2:0 planar
    Interlace mode:     None (Progressive)
    Chroma placement: MPEG-2
    No timecodes available
    supported.
  0 text tracks.

So it seems ffmpeg does the right thing, only misinforms about
its input.

>> Nope. It's bottom field first interlaced dv exported from
>> FinalCut. For simplicity I omitted the -deinterlace, and, for
>> testing, -top 0 options that I apply in my scripts because they
>> don't change the result.
> Not sure what this means, but I interpret is as being still interlaced. 
> ffmpeg misinterpretes fields and frames, for quit a long time.

Source is bottom field first interlaced dvvideo, like from a
camcorder -- well it /was/ from a camcorder before editing ;-)

c
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