Files
ppsspp/ext/ffmpeg/libavcodec/avfft.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

119 lines
3.0 KiB
C

/*
* 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
*/
#ifndef AVCODEC_AVFFT_H
#define AVCODEC_AVFFT_H
/**
* @file
* @ingroup lavc_fft
* FFT functions
*/
/**
* @defgroup lavc_fft FFT functions
* @ingroup lavc_misc
*
* @{
*/
typedef float FFTSample;
typedef struct FFTComplex {
FFTSample re, im;
} FFTComplex;
typedef struct FFTContext FFTContext;
/**
* Set up a complex FFT.
* @param nbits log2 of the length of the input array
* @param inverse if 0 perform the forward transform, if 1 perform the inverse
*/
FFTContext *av_fft_init(int nbits, int inverse);
/**
* Do the permutation needed BEFORE calling ff_fft_calc().
*/
void av_fft_permute(FFTContext *s, FFTComplex *z);
/**
* Do a complex FFT with the parameters defined in av_fft_init(). The
* input data must be permuted before. No 1.0/sqrt(n) normalization is done.
*/
void av_fft_calc(FFTContext *s, FFTComplex *z);
void av_fft_end(FFTContext *s);
FFTContext *av_mdct_init(int nbits, int inverse, double scale);
void av_imdct_calc(FFTContext *s, FFTSample *output, const FFTSample *input);
void av_imdct_half(FFTContext *s, FFTSample *output, const FFTSample *input);
void av_mdct_calc(FFTContext *s, FFTSample *output, const FFTSample *input);
void av_mdct_end(FFTContext *s);
/* Real Discrete Fourier Transform */
enum RDFTransformType {
DFT_R2C,
IDFT_C2R,
IDFT_R2C,
DFT_C2R,
};
typedef struct RDFTContext RDFTContext;
/**
* Set up a real FFT.
* @param nbits log2 of the length of the input array
* @param trans the type of transform
*/
RDFTContext *av_rdft_init(int nbits, enum RDFTransformType trans);
void av_rdft_calc(RDFTContext *s, FFTSample *data);
void av_rdft_end(RDFTContext *s);
/* Discrete Cosine Transform */
typedef struct DCTContext DCTContext;
enum DCTTransformType {
DCT_II = 0,
DCT_III,
DCT_I,
DST_I,
};
/**
* Set up DCT.
*
* @param nbits size of the input array:
* (1 << nbits) for DCT-II, DCT-III and DST-I
* (1 << nbits) + 1 for DCT-I
* @param type the type of transform
*
* @note the first element of the input of DST-I is ignored
*/
DCTContext *av_dct_init(int nbits, enum DCTTransformType type);
void av_dct_calc(DCTContext *s, FFTSample *data);
void av_dct_end (DCTContext *s);
/**
* @}
*/
#endif /* AVCODEC_AVFFT_H */