* AC-3 DSP utils
* Copyright (c) 2011 Justin Ruggles
*
- * 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
*/
#include <stdint.h>
+/**
+ * Number of mantissa bits written for each bap value.
+ * bap values with fractional bits are set to 0 and are calculated separately.
+ */
+extern const uint16_t ff_ac3_bap_bits[16];
+
typedef struct AC3DSPContext {
/**
* Set each encoded exponent in a block to the minimum of itself and the
* constraints: range [0,31]
*/
void (*ac3_rshift_int32)(int32_t *src, unsigned int len, unsigned int shift);
+
+ /**
+ * Convert an array of float in range [-1.0,1.0] to int32_t with range
+ * [-(1<<24),(1<<24)]
+ *
+ * @param dst destination array of int32_t.
+ * constraints: 16-byte aligned
+ * @param src source array of float.
+ * constraints: 16-byte aligned
+ * @param len number of elements to convert.
+ * constraints: multiple of 32 greater than zero
+ */
+ void (*float_to_fixed24)(int32_t *dst, const float *src, unsigned int len);
+
+ /**
+ * 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 (*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);
+
+ /**
+ * Update bap counts using the supplied array of bap.
+ *
+ * @param[out] mant_cnt bap counts for 1 block
+ * @param[in] bap array of bap, pointing to start coef bin
+ * @param[in] len number of elements to process
+ */
+ void (*update_bap_counts)(uint16_t mant_cnt[16], uint8_t *bap, int len);
+
+ /**
+ * Calculate the number of bits needed to encode a set of mantissas.
+ *
+ * @param[in] mant_cnt bap counts for all blocks
+ * @return mantissa bit count
+ */
+ int (*compute_mantissa_size)(uint16_t mant_cnt[6][16]);
+
+ void (*extract_exponents)(uint8_t *exp, int32_t *coef, int nb_coefs);
} AC3DSPContext;
-void ff_ac3dsp_init (AC3DSPContext *c);
-void ff_ac3dsp_init_x86(AC3DSPContext *c);
+void ff_ac3dsp_init (AC3DSPContext *c, int bit_exact);
+void ff_ac3dsp_init_arm(AC3DSPContext *c, int bit_exact);
+void ff_ac3dsp_init_x86(AC3DSPContext *c, int bit_exact);
#endif /* AVCODEC_AC3DSP_H */