Files
ppsspp/ext/ffmpeg/libavcodec/rdft.h
T
Henrik RydgårdandClaude Opus 5.5 d0e3141f43 FFmpeg: Vendor what PPSSPP uses into ext/ffmpeg, drop the submodule
The ffmpeg submodule held prebuilt libraries for every platform next to the
sources (about 1.5 GB checked out), and nothing uses those any more. Only the
needed sources are copied in, from the submodule's commit, along with every
header and template they include. The path is new, so checking out commits on
either side of this works.

It's also cut down to what PPSSPP uses: the H.264, AAC, MP3, ATRAC3 and ATRAC3+
decoders, the H.264 parser, the demuxers as before, and the FFV1 encoder, AVI
muxer and file protocol for AVI dumping. config.h takes its CONFIG_ values from
FFmpeg 3.0.2's own configure run with just those enabled. The raw H.264 demuxer
stays even though nothing opens raw H.264: probing PSMF data uses it to identify
the video stream's codec, which otherwise comes out as none.

On top of that:
- The files nothing links (configure would build them, but they're never pulled
  out of the static library, going by the GCC link map) are left out: mostly
  libavutil's crypto and hashing and the alternative DCT/IDCT/FFT versions.
- libswresample isn't built, now that nothing uses it.
- The H.264 decoder only does 8-bit video, which is all the PSP has. The SPS
  parser rejects any other bit depth, and the DSP files no longer build their 9-
  to 16-bit variants, which the linker kept because the init functions pick one
  by bit depth at run time.

That's 160 files to compile instead of 277, and 391 of FFmpeg's vendored, about
5.8 MB. The README in ext/ffmpeg has what was done, the PPSSPP patches in the
copy, how to add a component, and the tradeoffs.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
2026-10-25 22:27:54 +01:00

75 lines
2.0 KiB
C

/*
* (I)RDFT transforms
* Copyright (c) 2009 Alex Converse <alex dot converse at gmail dot com>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#if !defined(AVCODEC_RDFT_H) && (!defined(FFT_FLOAT) || FFT_FLOAT)
#define AVCODEC_RDFT_H
#include "config.h"
#include "fft.h"
#if CONFIG_HARDCODED_TABLES
# define SINTABLE_CONST const
#else
# define SINTABLE_CONST
#endif
#define SINTABLE(size) \
SINTABLE_CONST DECLARE_ALIGNED(16, FFTSample, ff_sin_##size)[size/2]
extern SINTABLE(16);
extern SINTABLE(32);
extern SINTABLE(64);
extern SINTABLE(128);
extern SINTABLE(256);
extern SINTABLE(512);
extern SINTABLE(1024);
extern SINTABLE(2048);
extern SINTABLE(4096);
extern SINTABLE(8192);
extern SINTABLE(16384);
extern SINTABLE(32768);
extern SINTABLE(65536);
struct RDFTContext {
int nbits;
int inverse;
int sign_convention;
/* pre/post rotation tables */
const FFTSample *tcos;
SINTABLE_CONST FFTSample *tsin;
FFTContext fft;
void (*rdft_calc)(struct RDFTContext *s, FFTSample *z);
};
/**
* Set up a real FFT.
* @param nbits log2 of the length of the input array
* @param trans the type of transform
*/
int ff_rdft_init(RDFTContext *s, int nbits, enum RDFTransformType trans);
void ff_rdft_end(RDFTContext *s);
void ff_rdft_init_arm(RDFTContext *s);
#endif /* AVCODEC_RDFT_H */