FFmpeg

113389 Commits

37 Branches

400 Tags

492 MiB

Tag: Branch: Tree: cad35f0a77

Commit Graph

Author	SHA1	Message	Date
Derek Buitenhuis	a2d3511154	lavc/ffv1: Properly check that the 4th and 5th quant tables are zeroes Currently, the decoder checks the 128th value of the 4th quant table during while deriving the context on each sample, in order to speed itself up. This is due to relying on the behavior of FFmpeg's FFV1 encoder, in which if that value is zero, the entire 4th and 5th quant tables are assumed to be entirely zero. This does not match the FFV1 spec, which has no such restriction, and after some discussion, it was decided to fix FFmpeg to abide by the spec, rather than change the spec. We will now check whether the 4th and 5th quant tables are zero properly, by checking the 128th valye of both tables (which means they are zero due to the way they're coded in the bitstream). For further context, the FFV1 issue in question is located at: https://github.com/FFmpeg/FFV1/issues/169 Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>	5 years ago
Michael Niedermayer	74314f1f5f	avcodec/ffv1: template functions to allow data types different from int16_t This is required for >= 16bit RGB support I tried it without templates but its too much duplicated code Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>	9 years ago

Author

SHA1

Message

Date

Derek Buitenhuis

a2d3511154

lavc/ffv1: Properly check that the 4th and 5th quant tables are zeroes

Currently, the decoder checks the 128th value of the 4th quant table during
while deriving the context on each sample, in order to speed itself up. This
is due to relying on the behavior of FFmpeg's FFV1 encoder, in which if that
value is zero, the entire 4th and 5th quant tables are assumed to be entirely
zero.

This does not match the FFV1 spec, which has no such restriction, and after
some discussion, it was decided to fix FFmpeg to abide by the spec, rather
than change the spec.

We will now check whether the 4th and 5th quant tables are zero properly,
by checking the 128th valye of both tables (which means they are zero due
to the way they're coded in the bitstream).

For further context, the FFV1 issue in question is located at:

    https://github.com/FFmpeg/FFV1/issues/169

Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

5 years ago

Michael Niedermayer

74314f1f5f

avcodec/ffv1: template functions to allow data types different from int16_t

This is required for >= 16bit RGB support
I tried it without templates but its too much duplicated code

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

9 years ago

2 Commits (cad35f0a7740a96740aa9367c401a36c86522245)