[Ffmpeg-devel] [RFC] D10 IMX patch encoding

Baptiste Coudurier baptiste.coudurier
Wed Jan 24 17:42:50 CET 2007


This patch add features to be able to encode D10 streams (SMPTE 356M,
also known as IMX)

Current rc code cannot support non linear quant, therefore, I workaround
mpeg2 quantizer to be able to put 1 as q_scale_type in bitstream,
meaning that qmax > 4 is not supported (yes, that's stupid but
q_scale_type 0 is forbidden in D10, and bitrate is either 30/40/50 Mb/s)

Add support for one mb per slice.

Add IMX bitstream filter to mux D10 stream into mov, and workaround to
set acceptable width/height by Final Cut, only PAL was tested. (coded
height is 608, while display height must be 576)

Command line to create IMX Final Cut compliant files with this patch:

ffmpeg -y -i <file> -minrate 50000k -maxrate 50000k -b 50000k -bufsize
2000000 -intra -flags +ildct+low_delay -dc 10 -flags2 +ivlc+non_linear_q
-rc_init_occupancy 2000000 -vcodec mpeg2video -slice_flags 8 -qmin 1
-qmax 4 -qscale 1 -vtag mx5p -vbsf imxdump IMX.mov

bufsize might need adjustment for 30/40 Mb/s.

use -qscale 1 else rc quantizer will get stucked at very high values
since bufsize is really small.

Baptiste COUDURIER                              GnuPG Key Id: 0x5C1ABAAA
SMARTJOG S.A.                                    http://www.smartjog.com
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Phone: +33 1 49966312
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