FFmpeg
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#include <stdint.h>
#include "libavutil/attributes.h"
#include "libavutil/avassert.h"
#include "libavutil/avstring.h"
#include "libavutil/channel_layout.h"
#include "libavutil/crc.h"
#include "libavutil/internal.h"
#include "libavutil/mem_internal.h"
#include "libavutil/opt.h"
#include "libavutil/thread.h"
#include "avcodec.h"
#include "codec_internal.h"
#include "config_components.h"
#include "encode.h"
#include "internal.h"
#include "me_cmp.h"
#include "put_bits.h"
#include "audiodsp.h"
#include "ac3dsp.h"
#include "ac3.h"
#include "ac3defs.h"
#include "ac3tab.h"
#include "fft.h"
#include "ac3enc.h"
#include "eac3enc.h"
Go to the source code of this file.
Data Structures | |
struct | AC3Mant |
Macros | |
#define | CMIXLEV_NUM_OPTIONS 3 |
#define | SURMIXLEV_NUM_OPTIONS 3 |
#define | EXTMIXLEV_NUM_OPTIONS 8 |
#define | OFFSET(param) offsetof(AC3EncodeContext, options.param) |
#define | AC3ENC_PARAM (AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_ENCODING_PARAM) |
#define | EXP_DIFF_THRESHOLD 500 |
Exponent Difference Threshold. More... | |
#define | CRC16_POLY ((1 << 0) | (1 << 2) | (1 << 15) | (1 << 16)) |
CRC-16 Polynomial. More... | |
#define | FLT_OPTION_THRESHOLD 0.01 |
Functions | |
void | ff_ac3_adjust_frame_size (AC3EncodeContext *s) |
Adjust the frame size to make the average bit rate match the target bit rate. More... | |
void | ff_ac3_compute_coupling_strategy (AC3EncodeContext *s) |
Set the initial coupling strategy parameters prior to coupling analysis. More... | |
static void | ac3_apply_rematrixing (AC3EncodeContext *s) |
Apply stereo rematrixing to coefficients based on rematrixing flags. More... | |
static av_cold void | exponent_init (void) |
static void | extract_exponents (AC3EncodeContext *s) |
static void | compute_exp_strategy (AC3EncodeContext *s) |
static void | encode_exponents_blk_ch (uint8_t *exp, int nb_exps, int exp_strategy, int cpl) |
Update the exponents so that they are the ones the decoder will decode. More... | |
static void | encode_exponents (AC3EncodeContext *s) |
static int | count_exponent_bits (AC3EncodeContext *s) |
static void | ac3_group_exponents (AC3EncodeContext *s) |
Group exponents. More... | |
static void | ac3_process_exponents (AC3EncodeContext *s) |
Calculate final exponents from the supplied MDCT coefficients and exponent shift. More... | |
static void | count_frame_bits_fixed (AC3EncodeContext *s) |
static av_cold void | bit_alloc_init (AC3EncodeContext *s) |
static void | count_frame_bits (AC3EncodeContext *s) |
static void | bit_alloc_masking (AC3EncodeContext *s) |
static void | reset_block_bap (AC3EncodeContext *s) |
static void | count_mantissa_bits_init (uint16_t mant_cnt[AC3_MAX_BLOCKS][16]) |
Initialize mantissa counts. More... | |
static void | count_mantissa_bits_update_ch (AC3EncodeContext *s, int ch, uint16_t mant_cnt[AC3_MAX_BLOCKS][16], int start, int end) |
Update mantissa bit counts for all blocks in 1 channel in a given bandwidth range. More... | |
static int | count_mantissa_bits (AC3EncodeContext *s) |
static int | bit_alloc (AC3EncodeContext *s, int snr_offset) |
Run the bit allocation with a given SNR offset. More... | |
static int | cbr_bit_allocation (AC3EncodeContext *s) |
static int | ac3_compute_bit_allocation (AC3EncodeContext *s) |
static int | sym_quant (int c, int e, int levels) |
Symmetric quantization on 'levels' levels. More... | |
static int | asym_quant (int c, int e, int qbits) |
Asymmetric quantization on 2^qbits levels. More... | |
static void | quantize_mantissas_blk_ch (AC3Mant *s, int32_t *fixed_coef, uint8_t *exp, uint8_t *bap, int16_t *qmant, int start_freq, int end_freq) |
Quantize a set of mantissas for a single channel in a single block. More... | |
static void | ac3_quantize_mantissas (AC3EncodeContext *s) |
Quantize mantissas using coefficients, exponents, and bit allocation pointers. More... | |
static void | ac3_output_frame_header (AC3EncodeContext *s) |
static void | output_audio_block (AC3EncodeContext *s, int blk) |
static unsigned int | mul_poly (unsigned int a, unsigned int b, unsigned int poly) |
static unsigned int | pow_poly (unsigned int a, unsigned int n, unsigned int poly) |
static void | output_frame_end (AC3EncodeContext *s) |
static void | ac3_output_frame (AC3EncodeContext *s, unsigned char *frame) |
Write the frame to the output bitstream. More... | |
int | ff_ac3_encode_frame_common_end (AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame, int *got_packet_ptr) |
static void | dprint_options (AC3EncodeContext *s) |
static int | validate_float_option (float v, const float *v_list, int v_list_size) |
static void | validate_mix_level (void *log_ctx, const char *opt_name, float *opt_param, const float *list, int list_size, int default_value, int min_value, int *ctx_param) |
int | ff_ac3_validate_metadata (AC3EncodeContext *s) |
Validate metadata options as set by AVOption system. More... | |
av_cold int | ff_ac3_encode_close (AVCodecContext *avctx) |
Finalize encoding and free any memory allocated by the encoder. More... | |
static av_cold int | set_channel_info (AVCodecContext *avctx) |
static av_cold int | validate_options (AC3EncodeContext *s) |
static av_cold void | set_bandwidth (AC3EncodeContext *s) |
static av_cold int | allocate_buffers (AC3EncodeContext *s) |
av_cold int | ff_ac3_encode_init (AVCodecContext *avctx) |
Variables | |
static const float | cmixlev_options [CMIXLEV_NUM_OPTIONS] |
static const float | surmixlev_options [SURMIXLEV_NUM_OPTIONS] |
static const float | extmixlev_options [EXTMIXLEV_NUM_OPTIONS] |
const AVOption | ff_ac3_enc_options [] |
const AVClass | ff_ac3enc_class |
const FFCodecDefault | ff_ac3_enc_defaults [] |
static uint8_t | exponent_group_tab [2][3][256] |
LUT for number of exponent groups. More... | |
const AVChannelLayout | ff_ac3_ch_layouts [19] |
List of supported channel layouts. More... | |
static const uint8_t | ac3_enc_channel_map [8][2][6] |
Table to remap channels from SMPTE order to AC-3 order. More... | |
static const uint8_t | ac3_bandwidth_tab [5][3][19] |
LUT to select the bandwidth code based on the bit rate, sample rate, and number of full-bandwidth channels. More... | |
static const int8_t | ac3_coupling_start_tab [6][3][19] |
LUT to select the coupling start band based on the bit rate, sample rate, and number of full-bandwidth channels. More... | |
static const uint8_t | exp_strategy_reuse_tab [4][6] |
Table used to select exponent strategy based on exponent reuse block interval. More... | |
The simplest AC-3 encoder.
Definition in file ac3enc.c.
#define OFFSET | ( | param | ) | offsetof(AC3EncodeContext, options.param) |
#define AC3ENC_PARAM (AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_ENCODING_PARAM) |
#define EXP_DIFF_THRESHOLD 500 |
#define CRC16_POLY ((1 << 0) | (1 << 2) | (1 << 15) | (1 << 16)) |
void ff_ac3_adjust_frame_size | ( | AC3EncodeContext * | s | ) |
Adjust the frame size to make the average bit rate match the target bit rate.
This is only needed for 11025, 22050, and 44100 sample rates or any E-AC-3.
s | AC-3 encoder private context |
Definition at line 307 of file ac3enc.c.
Referenced by encode_frame().
void ff_ac3_compute_coupling_strategy | ( | AC3EncodeContext * | s | ) |
Set the initial coupling strategy parameters prior to coupling analysis.
s | AC-3 encoder private context |
Definition at line 325 of file ac3enc.c.
Referenced by encode_frame().
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Apply stereo rematrixing to coefficients based on rematrixing flags.
s | AC-3 encoder private context |
Definition at line 396 of file ac3enc.c.
Referenced by ff_ac3_encode_frame_common_end().
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Definition at line 430 of file ac3enc.c.
Referenced by ff_ac3_encode_init().
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Definition at line 449 of file ac3enc.c.
Referenced by ac3_process_exponents().
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Definition at line 479 of file ac3enc.c.
Referenced by ac3_process_exponents().
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Update the exponents so that they are the ones the decoder will decode.
[in,out] | exp | array of exponents for 1 block in 1 channel |
nb_exps | number of exponents in active bandwidth | |
exp_strategy | exponent strategy for the block | |
cpl | indicates if the block is in the coupling channel |
Definition at line 545 of file ac3enc.c.
Referenced by encode_exponents().
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Definition at line 618 of file ac3enc.c.
Referenced by ac3_process_exponents().
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Definition at line 668 of file ac3enc.c.
Referenced by ac3_compute_bit_allocation().
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Group exponents.
3 delta-encoded exponents are in each 7-bit group. The number of groups varies depending on exponent strategy and bandwidth.
s | AC-3 encoder private context |
Definition at line 700 of file ac3enc.c.
Referenced by ff_ac3_encode_frame_common_end().
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Calculate final exponents from the supplied MDCT coefficients and exponent shift.
Extract exponents from MDCT coefficients, calculate exponent strategies, and encode final exponents.
s | AC-3 encoder private context |
Definition at line 758 of file ac3enc.c.
Referenced by ff_ac3_encode_frame_common_end().
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Definition at line 774 of file ac3enc.c.
Referenced by bit_alloc_init().
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Definition at line 883 of file ac3enc.c.
Referenced by ff_ac3_encode_init().
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Definition at line 919 of file ac3enc.c.
Referenced by ac3_compute_bit_allocation().
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Definition at line 1062 of file ac3enc.c.
Referenced by ac3_compute_bit_allocation().
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Definition at line 1092 of file ac3enc.c.
Referenced by bit_alloc(), and cbr_bit_allocation().
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Initialize mantissa counts.
These are set so that they are padded to the next whole group size when bits are counted in compute_mantissa_size.
[in,out] | mant_cnt | running counts for each bap value for each block |
Definition at line 1117 of file ac3enc.c.
Referenced by count_mantissa_bits().
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Update mantissa bit counts for all blocks in 1 channel in a given bandwidth range.
s | AC-3 encoder private context | |
ch | channel index | |
[in,out] | mant_cnt | running counts for each bap value for each block |
start | starting coefficient bin | |
end | ending coefficient bin |
Definition at line 1139 of file ac3enc.c.
Referenced by count_mantissa_bits().
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Definition at line 1159 of file ac3enc.c.
Referenced by bit_alloc().
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Run the bit allocation with a given SNR offset.
This calculates the bit allocation pointers that will be used to determine the quantization of each mantissa.
s | AC-3 encoder private context |
snr_offset | SNR offset, 0 to 1023 |
Definition at line 1185 of file ac3enc.c.
Referenced by cbr_bit_allocation(), compute_bit_allocation(), encode_frame(), mp_decode_layer2(), and MPA_encode_frame().
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Definition at line 1216 of file ac3enc.c.
Referenced by ac3_compute_bit_allocation().
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Definition at line 1267 of file ac3enc.c.
Referenced by ff_ac3_encode_frame_common_end().
Symmetric quantization on 'levels' levels.
c | unquantized coefficient |
e | exponent |
levels | number of quantization levels |
Definition at line 1287 of file ac3enc.c.
Referenced by quantize_mantissas_blk_ch().
Asymmetric quantization on 2^qbits levels.
c | unquantized coefficient |
e | exponent |
qbits | number of quantization bits |
Definition at line 1303 of file ac3enc.c.
Referenced by quantize_mantissas_blk_ch().
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Quantize a set of mantissas for a single channel in a single block.
s | Mantissa count context | |
fixed_coef | unquantized fixed-point coefficients | |
exp | exponents | |
bap | bit allocation pointer indices | |
[out] | qmant | quantized coefficients |
start_freq | starting coefficient bin | |
end_freq | ending coefficient bin |
Definition at line 1327 of file ac3enc.c.
Referenced by ac3_quantize_mantissas().
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Quantize mantissas using coefficients, exponents, and bit allocation pointers.
s | AC-3 encoder private context |
Definition at line 1422 of file ac3enc.c.
Referenced by ff_ac3_encode_frame_common_end().
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Definition at line 1451 of file ac3enc.c.
Referenced by ff_ac3_encode_init().
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Definition at line 1507 of file ac3enc.c.
Referenced by ac3_output_frame().
Definition at line 1700 of file ac3enc.c.
Referenced by output_frame_end(), and pow_poly().
Definition at line 1717 of file ac3enc.c.
Referenced by ff_ac3_encode_init().
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Definition at line 1734 of file ac3enc.c.
Referenced by ac3_output_frame().
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Write the frame to the output bitstream.
s | AC-3 encoder private context |
frame | output data buffer |
Definition at line 1783 of file ac3enc.c.
Referenced by ff_ac3_encode_frame_common_end().
int ff_ac3_encode_frame_common_end | ( | AVCodecContext * | avctx, |
AVPacket * | avpkt, | ||
const AVFrame * | frame, | ||
int * | got_packet_ptr | ||
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Definition at line 1797 of file ac3enc.c.
Referenced by encode_frame().
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Definition at line 1829 of file ac3enc.c.
Referenced by ff_ac3_encode_init().
Definition at line 1946 of file ac3enc.c.
Referenced by validate_mix_level().
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Definition at line 1962 of file ac3enc.c.
Referenced by ff_ac3_validate_metadata().
int ff_ac3_validate_metadata | ( | AC3EncodeContext * | s | ) |
Validate metadata options as set by AVOption system.
These values can optionally be changed per-frame.
s | AC-3 encoder private context |
Definition at line 1986 of file ac3enc.c.
Referenced by encode_frame(), and validate_options().
av_cold int ff_ac3_encode_close | ( | AVCodecContext * | avctx | ) |
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Definition at line 2216 of file ac3enc.c.
Referenced by validate_options().
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Definition at line 2263 of file ac3enc.c.
Referenced by ff_ac3_encode_init().
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Definition at line 2408 of file ac3enc.c.
Referenced by ff_ac3_encode_init().
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Definition at line 2478 of file ac3enc.c.
Referenced by ff_ac3_encode_init().
av_cold int ff_ac3_encode_init | ( | AVCodecContext * | avctx | ) |
Definition at line 2564 of file ac3enc.c.
Referenced by ac3_fixed_encode_init(), and ff_ac3_float_encode_init().
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Definition at line 62 of file ac3enc.c.
Referenced by ff_ac3_validate_metadata().
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Definition at line 67 of file ac3enc.c.
Referenced by ff_ac3_validate_metadata().
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Definition at line 72 of file ac3enc.c.
Referenced by ff_ac3_validate_metadata().
const AVClass ff_ac3enc_class |
const FFCodecDefault ff_ac3_enc_defaults[] |
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LUT for number of exponent groups.
exponent_group_tab[coupling][exponent strategy-1][number of coefficients]
Definition at line 148 of file ac3enc.c.
Referenced by ac3_group_exponents(), count_exponent_bits(), encode_exponents_blk_ch(), exponent_init(), and output_audio_block().
const AVChannelLayout ff_ac3_ch_layouts[19] |
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Table to remap channels from SMPTE order to AC-3 order.
[channel_mode][lfe][ch]
Definition at line 222 of file ac3enc.c.
Referenced by set_channel_info().
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LUT to select the bandwidth code based on the bit rate, sample rate, and number of full-bandwidth channels.
bandwidth_tab[fbw_channels-1][sample rate code][bit rate code]
Definition at line 233 of file ac3enc.c.
Referenced by set_bandwidth().
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LUT to select the coupling start band based on the bit rate, sample rate, and number of full-bandwidth channels.
-1 = coupling off ac3_coupling_start_tab[channel_mode-2][sample rate code][bit rate code]
TODO: more testing for optimal parameters. multi-channel tests at 44.1kHz and 32kHz.
Definition at line 266 of file ac3enc.c.
Referenced by set_bandwidth().
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Table used to select exponent strategy based on exponent reuse block interval.
Definition at line 468 of file ac3enc.c.
Referenced by compute_exp_strategy().