Chiebot-Mirror/FFmpeg - FFmpeg - Gitea: Git with a cup of tea

Author	SHA1	Message	Date
Andreas Rheinhardt	b52e0d9504	avcodec/atrac9tab: Unify tables used to initialize VLCs Using separate tables has the downside that one needs a big number of pointers to the separate tables (currently 77); unifying them avoids this. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>	4 years ago
Andreas Rheinhardt	5ac9d78dd2	avcodec/atrac9dec: Make tables used to initialize VLCs smaller The ATRAC9 decoder uses VLCs which are currently initialized with static length tables of type uint8_t and code tables of type uint16_t. Furthermore, in one case the actually desired symbols are in the range -16..15 and in order to achieve this an ad-hoc symbols table of type int16_t is calculated. This commit modifies this process by replacing the codes tables by symbols tables and switching to ff_init_vlc_from_lengths(); the signed symbols are stored in the table after having been shifted by 16 to fit into an uint8_t and are shifted back when the VLC is created. This makes all symbols fit into an uint8_t, saving space. Furthermore, the earlier tables had holes in them (entries with length zero that were inserted because the actually used symbols were not contiguous); these holes are unnecessary in the new approach, leading to further saving. Finally, given that now both lengths as well as symbols are of the same type, they can be combined; this saves a pointer for each VLC. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>	4 years ago
Andreas Rheinhardt	164ce14e5c	avcodec/atrac9tab: Add missing static to internal table Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>	4 years ago
Andreas Rheinhardt	92209cf4c9	avcodec/atrac9dec: Don't confuse max_depth of VLC with max codelength The whole point of VLCs with their tables is to read more than one bit at a time; therefore max_depth, the number of times one has to (maximally) read further bits is given by ceil(max_code_length / table_bits) which in the case of ATRAC9's coefficient VLCs gives an upper bound of two. Instead the maximum length of a code of the given VLC has been used (which is not even a compile-time constant). Use two instead. Furthermore, given that this was the only usage of the field containing the maximum of all the code lengths of a given VLC the field has been removed from its containing struct. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>	4 years ago
James Almer	78a24fd014	avcodec/atrac9tab: use explicit ATRAC9BlockConfig struct initializers Cosmetic change. Reviewed-by: Lynne <dev@lynne.ee> Signed-off-by: James Almer <jamrial@gmail.com>	5 years ago
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