Re: [libdv-dev] Possible bug encoding interlaced material?

[Steven M. S. <sm...@2B...>]

On Fri, 8 Apr 2005, Jonathan Woithe wrote:

> From DV to MPEG2 I use tools only from mjpegtools.  These do of course use
> libdv's decoder.  I haven't as yet had time to work out how to get ffmpeg
> into the pipeline - I'll see if time allows such experiments over the

	The way I use ffmpeg's dv decoder is to build the smilutils against
	ffmpeg/libavcodec (in the smilutils configure it's "--with-avcodec 
	--with-avcodec-include=yourdirectorytolibavcode").
	
	smilutils is on the Kino site somewhere as I recall (I checked it out
	from cvs ':pserver:ano...@cv...:/cvsroot/kino' and
	project/module 'smilutils').  By default smilutils builds with libdv
	but it can also work with ffmpeg/libavcodec

> weekend.  Anyway, given a DV stream (in a QT container, but that's not
> relevant for this), the process at its simplest form is
> 
>   lav2yuv foo.mov | mpeg2enc -f 8 -q 6 -N 0.5 -E -10 -c -s \

	^lav2yuv^smil2yuv^

> were foo.mov is a raw DV stream encapsulated in a Quicktime file.

	My preference is for 'raw DV' - makes using 'dd' as a poor man's 
	editor trivial (fixed record size) and less overhead.

> I haven't yet had a chance to look into how one could use ffmpeg to do the
> DV->YUV4MPEG conversion - it's another thing for the weekend.  Based on the

	ffmpeg can produce raw 420planar data - once you have that then the
	little utility from mjpegtools called 'yuv4mpeg' can be used to put
	the YUV4MPEG2 headers/framemarkers in.

> of difference.  As far as the decoders go, ffmpeg and libdv seem (at first
> glance anyway) to give equivalent output.

	When I switched from libdv to smilutil+libavcodec/dv the average
	bitrate of the final MPEG-2 file was 10-15% *lower* (and ALL other
	parameters/programs in the pipeline were the same).  Your mileage
	may vary of course.

	Cheers,
	Steven Schultz