Commit 07965463 authored by Justin Ruggles's avatar Justin Ruggles
Browse files

cosmetics: Document AC3EncodeContext fields.

Originally committed as revision 25953 to svn://svn.ffmpeg.org/ffmpeg/trunk
parent 22c0b03c
......@@ -34,41 +34,45 @@
#include "audioconvert.h"
typedef struct AC3EncodeContext {
PutBitContext pb;
PutBitContext pb; ///< bitstream writer context
int bitstream_id;
int bitstream_mode;
int bitstream_id; ///< bitstream id (bsid)
int bitstream_mode; ///< bitstream mode (bsmod)
int bit_rate;
int sample_rate;
int bit_rate; ///< target bit rate, in bits-per-second
int sample_rate; ///< sampling frequency, in Hz
int frame_size_min; /* minimum frame size in case rounding is necessary */
int frame_size; /* current frame size in words */
int frame_size_code;
int bits_written;
int samples_written;
int frame_size_min; ///< minimum frame size in case rounding is necessary
int frame_size; ///< current frame size in words
int frame_size_code; ///< frame size code (frmsizecod)
int bits_written; ///< bit count (used to avg. bitrate)
int samples_written; ///< sample count (used to avg. bitrate)
int fbw_channels;
int channels;
int lfe_on;
int lfe_channel;
int channel_mode;
const uint8_t *channel_map;
int fbw_channels; ///< number of full-bandwidth channels (nfchans)
int channels; ///< total number of channels (nchans)
int lfe_on; ///< indicates if there is an LFE channel (lfeon)
int lfe_channel; ///< channel index of the LFE channel
int channel_mode; ///< channel mode (acmod)
const uint8_t *channel_map; ///< channel map used to reorder channels
int bandwidth_code[AC3_MAX_CHANNELS];
int bandwidth_code[AC3_MAX_CHANNELS]; ///< bandwidth code (0 to 60) (chbwcod)
int nb_coefs[AC3_MAX_CHANNELS];
/* bitrate allocation control */
int slow_gain_code, slow_decay_code, fast_decay_code, db_per_bit_code, floor_code;
AC3BitAllocParameters bit_alloc;
int coarse_snr_offset;
int fast_gain_code[AC3_MAX_CHANNELS];
int fine_snr_offset[AC3_MAX_CHANNELS];
int slow_gain_code; ///< slow gain code (sgaincod)
int slow_decay_code; ///< slow decay code (sdcycod)
int fast_decay_code; ///< fast decay code (fdcycod)
int db_per_bit_code; ///< dB/bit code (dbpbcod)
int floor_code; ///< floor code (floorcod)
AC3BitAllocParameters bit_alloc; ///< bit allocation parameters
int coarse_snr_offset; ///< coarse SNR offsets (csnroffst)
int fast_gain_code[AC3_MAX_CHANNELS]; ///< fast gain codes (signal-to-mask ratio) (fgaincod)
int fine_snr_offset[AC3_MAX_CHANNELS]; ///< fine SNR offsets (fsnroffst)
/* mantissa encoding */
int mant1_cnt, mant2_cnt, mant4_cnt;
int mant1_cnt, mant2_cnt, mant4_cnt; ///< mantissa counts for bap=1,2,4
int16_t last_samples[AC3_MAX_CHANNELS][AC3_BLOCK_SIZE];
int16_t last_samples[AC3_MAX_CHANNELS][AC3_BLOCK_SIZE]; ///< last 256 samples from previous frame
} AC3EncodeContext;
static int16_t costab[64];
......
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