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Diffstat (limited to 'contrib/ffmpeg/libavcodec/ac3.h')
| -rw-r--r-- | contrib/ffmpeg/libavcodec/ac3.h | 171 |
1 files changed, 0 insertions, 171 deletions
diff --git a/contrib/ffmpeg/libavcodec/ac3.h b/contrib/ffmpeg/libavcodec/ac3.h deleted file mode 100644 index ae53a80c3..000000000 --- a/contrib/ffmpeg/libavcodec/ac3.h +++ /dev/null @@ -1,171 +0,0 @@ -/* - * Common code between AC3 encoder and decoder - * Copyright (c) 2000, 2001, 2002 Fabrice Bellard. - * - * 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 - */ - -/** - * @file ac3.h - * Common code between AC3 encoder and decoder. - */ - -#define AC3_MAX_CODED_FRAME_SIZE 3840 /* in bytes */ -#define AC3_MAX_CHANNELS 6 /* including LFE channel */ - -#define NB_BLOCKS 6 /* number of PCM blocks inside an AC3 frame */ -#define AC3_FRAME_SIZE (NB_BLOCKS * 256) - -/* exponent encoding strategy */ -#define EXP_REUSE 0 -#define EXP_NEW 1 - -#define EXP_D15 1 -#define EXP_D25 2 -#define EXP_D45 3 - -typedef struct AC3BitAllocParameters { - int fscod; /* frequency */ - int halfratecod; - int sgain, sdecay, fdecay, dbknee, floor; - int cplfleak, cplsleak; -} AC3BitAllocParameters; - -/** - * @struct AC3HeaderInfo - * Coded AC-3 header values up to the lfeon element, plus derived values. - */ -typedef struct { - /** @defgroup coded Coded elements - * @{ - */ - uint16_t sync_word; - uint16_t crc1; - uint8_t fscod; - uint8_t frmsizecod; - uint8_t bsid; - uint8_t bsmod; - uint8_t acmod; - uint8_t cmixlev; - uint8_t surmixlev; - uint8_t dsurmod; - uint8_t lfeon; - /** @} */ - - /** @defgroup derived Derived values - * @{ - */ - uint8_t halfratecod; - uint16_t sample_rate; - uint32_t bit_rate; - uint8_t channels; - uint16_t frame_size; - /** @} */ -} AC3HeaderInfo; - -/** - * Parses AC-3 frame header. - * Parses the header up to the lfeon element, which is the first 52 or 54 bits - * depending on the audio coding mode. - * @param buf[in] Array containing the first 7 bytes of the frame. - * @param hdr[out] Pointer to struct where header info is written. - * @return Returns 0 on success, -1 if there is a sync word mismatch, - * -2 if the bsid (version) element is invalid, -3 if the fscod (sample rate) - * element is invalid, or -4 if the frmsizecod (bit rate) element is invalid. - */ -int ff_ac3_parse_header(const uint8_t buf[7], AC3HeaderInfo *hdr); - -extern const uint16_t ff_ac3_frame_sizes[38][3]; -extern const uint8_t ff_ac3_channels[8]; -extern const uint16_t ff_ac3_freqs[3]; -extern const uint16_t ff_ac3_bitratetab[19]; -extern const int16_t ff_ac3_window[256]; -extern const uint8_t ff_sdecaytab[4]; -extern const uint8_t ff_fdecaytab[4]; -extern const uint16_t ff_sgaintab[4]; -extern const uint16_t ff_dbkneetab[4]; -extern const int16_t ff_floortab[8]; -extern const uint16_t ff_fgaintab[8]; - -void ac3_common_init(void); - -/** - * Calculates the log power-spectral density of the input signal. - * This gives a rough estimate of signal power in the frequency domain by using - * the spectral envelope (exponents). The psd is also separately grouped - * into critical bands for use in the calculating the masking curve. - * 128 units in psd = -6 dB. The dbknee parameter in AC3BitAllocParameters - * determines the reference level. - * - * @param[in] exp frequency coefficient exponents - * @param[in] start starting bin location - * @param[in] end ending bin location - * @param[out] psd signal power for each frequency bin - * @param[out] bndpsd signal power for each critical band - */ -void ff_ac3_bit_alloc_calc_psd(int8_t *exp, int start, int end, int16_t *psd, - int16_t *bndpsd); - -/** - * Calculates the masking curve. - * First, the excitation is calculated using parameters in \p s and the signal - * power in each critical band. The excitation is compared with a predefined - * hearing threshold table to produce the masking curve. If delta bit - * allocation information is provided, it is used for adjusting the masking - * curve, usually to give a closer match to a better psychoacoustic model. - * - * @param[in] s adjustable bit allocation parameters - * @param[in] bndpsd signal power for each critical band - * @param[in] start starting bin location - * @param[in] end ending bin location - * @param[in] fgain fast gain (estimated signal-to-mask ratio) - * @param[in] is_lfe whether or not the channel being processed is the LFE - * @param[in] deltbae delta bit allocation exists (none, reuse, or new) - * @param[in] deltnseg number of delta segments - * @param[in] deltoffst location offsets for each segment - * @param[in] deltlen length of each segment - * @param[in] deltba delta bit allocation for each segment - * @param[out] mask calculated masking curve - */ -void ff_ac3_bit_alloc_calc_mask(AC3BitAllocParameters *s, int16_t *bndpsd, - int start, int end, int fgain, int is_lfe, - int deltbae, int deltnseg, uint8_t *deltoffst, - uint8_t *deltlen, uint8_t *deltba, - int16_t *mask); - -/** - * Calculates bit allocation pointers. - * The SNR is the difference between the masking curve and the signal. AC-3 - * uses this value for each frequency bin to allocate bits. The \p snroffset - * parameter is a global adjustment to the SNR for all bins. - * - * @param[in] mask masking curve - * @param[in] psd signal power for each frequency bin - * @param[in] start starting bin location - * @param[in] end ending bin location - * @param[in] snroffset SNR adjustment - * @param[in] floor noise floor - * @param[out] bap bit allocation pointers - */ -void ff_ac3_bit_alloc_calc_bap(int16_t *mask, int16_t *psd, int start, int end, - int snroffset, int floor, uint8_t *bap); - -void ac3_parametric_bit_allocation(AC3BitAllocParameters *s, uint8_t *bap, - int8_t *exp, int start, int end, - int snroffset, int fgain, int is_lfe, - int deltbae,int deltnseg, - uint8_t *deltoffst, uint8_t *deltlen, uint8_t *deltba); |