[FFmpeg-user] Capture from USB Dazzle: Interlaced or not interlaced. FFV1 level3 vs h264

Andy Furniss adf.lists at gmail.com
Mon Nov 2 15:14:24 CET 2015

MrNice wrote:
> On 02/11/15 10:26, MrNice wrote:
>> I had a closer look on what I did previously. With FFV1, option
>> -flags +ilme+ildct do nothing. Debug see it but do nothing => I'll
>> remove it Moreover, documentation says: Apply interlaced motion
>> estimation, Use interlaced DCT (MPEG-2 and MPEG-4 only)
>> With x264, debug returns a warning: interlace + weightp is not
>> implemented

That warning is harmless and libx264 always gives it if you encode

>> This option is not in the CL. When I remove +ildct, the warning
>> disappears.
>> => I'd guess +ildct is useless, I'll remove it
>> Let me know what you think

I already said to use x264opts rather than flags so at least you get to
choose field dominance. You also need setfield to make ffprobe show the
correct field dominance.

What would be interesting to see is the output a v4l capture with debug
to see if v4l2 somewhere lists the field dominance of the frames it
outputs eg.

./ffmpeg -loglevel debug -f v4l2 -ts mono2abs -channel 1 -video_size 
720x576 -pix_fmt yuyv422 -thread_queue_size 512 -i /dev/video0 -t 1 -f 
null -

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