FFmpeg

94582 Commits

37 Branches

400 Tags

492 MiB

Tag: Branch: Tree: 67889d4715

Commit Graph

Author	SHA1	Message	Date
James Almer	a61b56624b	avcodec/atrac9tab: add missing header include Fixes make checkheaders Signed-off-by: James Almer <jamrial@gmail.com>	7 years ago
Carl Eugen Hoyos	e25c25ebd8	lavc/atrac9tab: Add inclusion guards. Fixes fate-source.	7 years ago
Rostislav Pehlivanov	755e618399	lavc: implement an ATRAC9 decoder This commit implements a full ATRAC9 decoder, a simple low-delay codec developed by Sony and used in most PSVita games, some PS3 games and some PS4 games. Its similar to AAC in that it uses Huffman coded scalefactors but instead of vector quantization it just Huffman codes the spectral coefficients (in a way similar to how Opus splits band energy coding into coarse and fine precision). It opts to write rather large Huffman codes by packing several small coefficients into one Huffman coded symbol, though I don't believe this increases efficiency at all. Band extension implements SBC in a simple way, first it mirrors the lower spectrum onto the higher frequencies and then it uses one of 5 filters to shape it. Noise substitution is implemented via 2 of them. Unlike previous ATRAC codecs, there's no QMF, this is a standard MDCT codec. Based off of the reverse engineering work of Alex Barney. Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>	7 years ago

Author

SHA1

Message

Date

James Almer

a61b56624b

avcodec/atrac9tab: add missing header include

Fixes make checkheaders

Signed-off-by: James Almer <jamrial@gmail.com>

7 years ago

Carl Eugen Hoyos

e25c25ebd8

lavc/atrac9tab: Add inclusion guards.

Fixes fate-source.

7 years ago

Rostislav Pehlivanov

755e618399

lavc: implement an ATRAC9 decoder

This commit implements a full ATRAC9 decoder, a simple low-delay codec
developed by Sony and used in most PSVita games, some PS3 games and some
PS4 games. Its similar to AAC in that it uses Huffman coded scalefactors
but instead of vector quantization it just Huffman codes the spectral
coefficients (in a way similar to how Opus splits band energy coding
into coarse and fine precision). It opts to write rather large Huffman
codes by packing several small coefficients into one Huffman coded
symbol, though I don't believe this increases efficiency at all.
Band extension implements SBC in a simple way, first it mirrors the
lower spectrum onto the higher frequencies and then it uses one of 5
filters to shape it. Noise substitution is implemented via 2 of them.
Unlike previous ATRAC codecs, there's no QMF, this is a standard MDCT
codec.

Based off of the reverse engineering work of Alex Barney.

Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>

7 years ago

3 Commits (67889d4715d4a65864fedba1b8e5e2918bd8152a)