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saloromer / ffmbc

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FFmbc should check mpeg-2 essence D-10 compliance when muxing as D-10 #4

Closed GoogleCodeExporter closed 8 years ago

GoogleCodeExporter commented 8 years ago 
To create a valid IMX D-10 files, from a generic MPEG2 Transport Stream, FFmbc 
can 
simply re-wrap rather than transcode the source file.

However, an IMX D-10 file requires "zig-zag" rather than "alternate" scan 
method for run-
length coding of the quantized DCT coefficients. This is set by a bit in the 
picture layer 
header. Many interlaced MPEG2 Transport Stream files use "alternate" scanning 
to 
improve compression.

Currently FFmbc does not check the scanning bit and creates what appears to be 
a valid 
IMX D-10 file. On testing, this file does not work as expected in QuickTime or 
Final Cut 
Pro, due to non-compatible scan method.

Proposal for IMX D-10 file creation is:

1. FFmbc to detect scan method used on input file
2. FFmbc to warn user if "alternate" scan method used in input file
3. User chooses to continue or abort
4. If user continues, file is transcoded using FFmbc, rather than re-wrapped, 
to create valid 
IMX D-10 file with zig-zan scan method.

Original issue reported on code.google.com by phillclarke@gmail.com on 12 Nov 2009 at 11:40

GoogleCodeExporter commented 8 years ago 
Well, I believe this is a bit too complicated.

mov muxer will simply fail if mpeg-2 input bistream is not D-10 compliant.

Original comment by baptiste...@gmail.com on 12 Nov 2009 at 11:48

GoogleCodeExporter commented 8 years ago 
OK, but please make it fail elegently with a decipherable reason and suggested 
alternative. 

E.g. MPEG2 input bitstream is not D-10 compliant. You'll have to transcode the 
file using <insert relevant 
FFmbc flags> instead.

Original comment by phillclarke@gmail.com on 12 Nov 2009 at 11:56

GoogleCodeExporter commented 8 years ago

Original comment by baptiste...@gmail.com on 3 May 2010 at 5:33

GoogleCodeExporter commented 8 years ago

Original comment by baptiste...@gmail.com on 26 Jul 2011 at 10:56