mirror of
https://git.ffmpeg.org/ffmpeg.git
synced 2024-12-13 10:44:59 +00:00
33 lines
1.0 KiB
C
33 lines
1.0 KiB
C
|
|
||
|
|
#define AC3_FRAME_SIZE (6*256)
|
||
|
|
#define AC3_MAX_CODED_FRAME_SIZE 3840 /* in bytes */
|
||
|
|
#define AC3_MAX_CHANNELS 2 /* we handle at most two channels, although
|
||
|
|
AC3 allows 6 channels */
|
||
|
|
|
||
|
|
typedef struct AC3EncodeContext {
|
||
|
|
PutBitContext pb;
|
||
|
|
int nb_channels;
|
||
|
|
int bit_rate;
|
||
|
|
int sample_rate;
|
||
|
|
int bsid;
|
||
|
|
int frame_size_min; /* minimum frame size in case rounding is necessary */
|
||
|
|
int frame_size; /* current frame size in words */
|
||
|
|
int halfratecod;
|
||
|
|
int frmsizecod;
|
||
|
|
int fscod; /* frequency */
|
||
|
|
int acmod;
|
||
|
|
int bsmod;
|
||
|
|
short last_samples[AC3_MAX_CHANNELS][256];
|
||
|
|
int chbwcod[AC3_MAX_CHANNELS];
|
||
|
|
int nb_coefs[AC3_MAX_CHANNELS];
|
||
|
|
|
||
|
|
/* bitrate allocation control */
|
||
|
|
int sgaincod, sdecaycod, fdecaycod, dbkneecod, floorcod;
|
||
|
|
int sgain, sdecay, fdecay, dbknee, floor;
|
||
|
|
int csnroffst;
|
||
|
|
int fgaincod[AC3_MAX_CHANNELS];
|
||
|
|
int fsnroffst[AC3_MAX_CHANNELS];
|
||
|
|
/* mantissa encoding */
|
||
|
|
int mant1_cnt, mant2_cnt, mant4_cnt;
|
||
|
|
} AC3EncodeContext;
|