* Common code between the AC-3 encoder and decoder
* Copyright (c) 2000, 2001, 2002 Fabrice Bellard
*
- * This file is part of FFmpeg.
+ * This file is part of Libav.
*
- * FFmpeg is free software; you can redistribute it and/or
+ * Libav 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,
+ * Libav 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
+ * License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef AVCODEC_AC3_H
#define AVCODEC_AC3_H
-#include "ac3tab.h"
-
#define AC3_MAX_CODED_FRAME_SIZE 3840 /* in bytes */
-#define AC3_MAX_CHANNELS 6 /* including LFE channel */
+#define AC3_MAX_CHANNELS 7 /**< maximum number of channels, including coupling channel */
+#define CPL_CH 0 /**< coupling channel index */
#define AC3_MAX_COEFS 256
#define AC3_BLOCK_SIZE 256
#define AC3_MAX_BLOCKS 6
#define AC3_FRAME_SIZE (AC3_MAX_BLOCKS * 256)
+#define AC3_WINDOW_SIZE (AC3_BLOCK_SIZE * 2)
+#define AC3_CRITICAL_BANDS 50
+#define AC3_MAX_CPL_BANDS 18
+
+#include "ac3tab.h"
/* exponent encoding strategy */
#define EXP_REUSE 0
#define EXP_D25 2
#define EXP_D45 3
+/* pre-defined gain values */
+#define LEVEL_PLUS_3DB 1.4142135623730950
+#define LEVEL_PLUS_1POINT5DB 1.1892071150027209
+#define LEVEL_MINUS_1POINT5DB 0.8408964152537145
+#define LEVEL_MINUS_3DB 0.7071067811865476
+#define LEVEL_MINUS_4POINT5DB 0.5946035575013605
+#define LEVEL_MINUS_6DB 0.5000000000000000
+#define LEVEL_MINUS_9DB 0.3535533905932738
+#define LEVEL_ZERO 0.0000000000000000
+#define LEVEL_ONE 1.0000000000000000
+
/** Delta bit allocation strategy */
typedef enum {
DBA_REUSE = 0,
AC3_CHMODE_3F2R
} AC3ChannelMode;
+/** Dolby Surround mode */
+typedef enum AC3DolbySurroundMode {
+ AC3_DSURMOD_NOTINDICATED = 0,
+ AC3_DSURMOD_OFF,
+ AC3_DSURMOD_ON,
+ AC3_DSURMOD_RESERVED
+} AC3DolbySurroundMode;
+
+/** Dolby Surround EX mode */
+typedef enum AC3DolbySurroundEXMode {
+ AC3_DSUREXMOD_NOTINDICATED = 0,
+ AC3_DSUREXMOD_OFF,
+ AC3_DSUREXMOD_ON,
+ AC3_DSUREXMOD_PLIIZ
+} AC3DolbySurroundEXMode;
+
+/** Dolby Headphone mode */
+typedef enum AC3DolbyHeadphoneMode {
+ AC3_DHEADPHONMOD_NOTINDICATED = 0,
+ AC3_DHEADPHONMOD_OFF,
+ AC3_DHEADPHONMOD_ON,
+ AC3_DHEADPHONMOD_RESERVED
+} AC3DolbyHeadphoneMode;
+
+/** Preferred Stereo Downmix mode */
+typedef enum AC3PreferredStereoDownmixMode {
+ AC3_DMIXMOD_NOTINDICATED = 0,
+ AC3_DMIXMOD_LTRT,
+ AC3_DMIXMOD_LORO,
+ AC3_DMIXMOD_DPLII // reserved value in A/52, but used by encoders to indicate DPL2
+} AC3PreferredStereoDownmixMode;
+
typedef struct AC3BitAllocParameters {
int sr_code;
int sr_shift;
* @struct AC3HeaderInfo
* Coded AC-3 header values up to the lfeon element, plus derived values.
*/
-typedef struct {
- /** @defgroup coded Coded elements
+typedef struct AC3HeaderInfo {
+ /** @name Coded elements
* @{
*/
uint16_t sync_word;
uint16_t crc1;
uint8_t sr_code;
uint8_t bitstream_id;
+ uint8_t bitstream_mode;
uint8_t channel_mode;
uint8_t lfe_on;
uint8_t frame_type;
int surround_mix_level; ///< Surround mix level index
uint16_t channel_map;
int num_blocks; ///< number of audio blocks
+ int dolby_surround_mode;
/** @} */
- /** @defgroup derived Derived values
+ /** @name Derived values
* @{
*/
uint8_t sr_shift;
uint32_t bit_rate;
uint8_t channels;
uint16_t frame_size;
- int64_t channel_layout;
+ uint64_t channel_layout;
/** @} */
} AC3HeaderInfo;
EAC3_FRAME_TYPE_RESERVED
} EAC3FrameType;
-void ac3_common_init(void);
+void ff_ac3_common_init(void);
/**
* Calculate the log power-spectral density of the input signal.
uint8_t *dba_lengths, uint8_t *dba_values,
int16_t *mask);
-/**
- * Calculate 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 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] snr_offset SNR adjustment
- * @param[in] floor noise floor
- * @param[in] bap_tab look-up table for bit allocation pointers
- * @param[out] bap bit allocation pointers
- */
-void ff_ac3_bit_alloc_calc_bap(int16_t *mask, int16_t *psd, int start, int end,
- int snr_offset, int floor,
- const uint8_t *bap_tab, uint8_t *bap);
-
-void ac3_parametric_bit_allocation(AC3BitAllocParameters *s, uint8_t *bap,
- int8_t *exp, int start, int end,
- int snr_offset, int fast_gain, int is_lfe,
- int dba_mode, int dba_nsegs,
- uint8_t *dba_offsets, uint8_t *dba_lengths,
- uint8_t *dba_values);
-
#endif /* AVCODEC_AC3_H */
projects / ffmpeg / blobdiff