/** Scale a float value by 2^bits and convert to an integer. */
#define SCALE_FLOAT(a, bits) lrintf((a) * (float)(1 << (bits)))
+typedef int16_t SampleType;
+typedef int32_t CoefType;
+
+#define SCALE_COEF(a) (a)
+
/** Scale a float value by 2^15, convert to an integer, and clip to range -32767..32767. */
#define FIX15(a) av_clip(SCALE_FLOAT(a, 15), -32767, 32767)
} IComplex;
typedef struct AC3MDCTContext {
- AVCodecContext *avctx; ///< parent context for av_log()
+ const int16_t *window; ///< MDCT window function
int nbits; ///< log2(transform size)
int16_t *costab; ///< FFT cos table
int16_t *sintab; ///< FFT sin table
*/
typedef struct AC3Block {
uint8_t **bap; ///< bit allocation pointers (bap)
- int32_t **mdct_coef; ///< MDCT coefficients
+ CoefType **mdct_coef; ///< MDCT coefficients
uint8_t **exp; ///< original exponents
uint8_t **grouped_exp; ///< grouped exponents
int16_t **psd; ///< psd per frequency bin
int16_t **planar_samples;
uint8_t *bap_buffer;
uint8_t *bap1_buffer;
- int32_t *mdct_coef_buffer;
+ CoefType *mdct_coef_buffer;
uint8_t *exp_buffer;
uint8_t *grouped_exp_buffer;
int16_t *psd_buffer;
int16_t *mask_buffer;
uint16_t *qmant_buffer;
- DECLARE_ALIGNED(16, int16_t, windowed_samples)[AC3_WINDOW_SIZE];
+ DECLARE_ALIGNED(16, SampleType, windowed_samples)[AC3_WINDOW_SIZE];
} AC3EncodeContext;
* LUT for number of exponent groups.
* exponent_group_tab[exponent strategy-1][number of coefficients]
*/
-uint8_t exponent_group_tab[3][256];
+static uint8_t exponent_group_tab[3][256];
+
+
+/**
+ * List of supported channel layouts.
+ */
+static const int64_t ac3_channel_layouts[] = {
+ AV_CH_LAYOUT_MONO,
+ AV_CH_LAYOUT_STEREO,
+ AV_CH_LAYOUT_2_1,
+ AV_CH_LAYOUT_SURROUND,
+ AV_CH_LAYOUT_2_2,
+ AV_CH_LAYOUT_QUAD,
+ AV_CH_LAYOUT_4POINT0,
+ AV_CH_LAYOUT_5POINT0,
+ AV_CH_LAYOUT_5POINT0_BACK,
+ (AV_CH_LAYOUT_MONO | AV_CH_LOW_FREQUENCY),
+ (AV_CH_LAYOUT_STEREO | AV_CH_LOW_FREQUENCY),
+ (AV_CH_LAYOUT_2_1 | AV_CH_LOW_FREQUENCY),
+ (AV_CH_LAYOUT_SURROUND | AV_CH_LOW_FREQUENCY),
+ (AV_CH_LAYOUT_2_2 | AV_CH_LOW_FREQUENCY),
+ (AV_CH_LAYOUT_QUAD | AV_CH_LOW_FREQUENCY),
+ (AV_CH_LAYOUT_4POINT0 | AV_CH_LOW_FREQUENCY),
+ AV_CH_LAYOUT_5POINT1,
+ AV_CH_LAYOUT_5POINT1_BACK,
+ 0
+};
/**
* Channels are reordered from FFmpeg's default order to AC-3 order.
*/
static void deinterleave_input_samples(AC3EncodeContext *s,
- const int16_t *samples)
+ const SampleType *samples)
{
int ch, i;
/* deinterleave and remap input samples */
for (ch = 0; ch < s->channels; ch++) {
- const int16_t *sptr;
+ const SampleType *sptr;
int sinc;
/* copy last 256 samples of previous frame to the start of the current frame */
}
-
/**
* Initialize FFT tables.
* @param ln log2(FFT size)
*/
-static av_cold int fft_init(AC3MDCTContext *mdct, int ln)
+static av_cold int fft_init(AVCodecContext *avctx, AC3MDCTContext *mdct, int ln)
{
int i, n, n2;
float alpha;
n = 1 << ln;
n2 = n >> 1;
- FF_ALLOC_OR_GOTO(mdct->avctx, mdct->costab, n2 * sizeof(*mdct->costab),
- fft_alloc_fail);
- FF_ALLOC_OR_GOTO(mdct->avctx, mdct->sintab, n2 * sizeof(*mdct->sintab),
- fft_alloc_fail);
+ FF_ALLOC_OR_GOTO(avctx, mdct->costab, n2 * sizeof(*mdct->costab), fft_alloc_fail);
+ FF_ALLOC_OR_GOTO(avctx, mdct->sintab, n2 * sizeof(*mdct->sintab), fft_alloc_fail);
for (i = 0; i < n2; i++) {
alpha = 2.0 * M_PI * i / n;
* Initialize MDCT tables.
* @param nbits log2(MDCT size)
*/
-static av_cold int mdct_init(AC3MDCTContext *mdct, int nbits)
+static av_cold int mdct_init(AVCodecContext *avctx, AC3MDCTContext *mdct,
+ int nbits)
{
int i, n, n4, ret;
mdct->nbits = nbits;
- ret = fft_init(mdct, nbits - 2);
+ ret = fft_init(avctx, mdct, nbits - 2);
if (ret)
return ret;
- FF_ALLOC_OR_GOTO(mdct->avctx, mdct->xcos1, n4 * sizeof(*mdct->xcos1),
- mdct_alloc_fail);
- FF_ALLOC_OR_GOTO(mdct->avctx, mdct->xsin1 , n4 * sizeof(*mdct->xsin1),
- mdct_alloc_fail);
- FF_ALLOC_OR_GOTO(mdct->avctx, mdct->rot_tmp, n * sizeof(*mdct->rot_tmp),
- mdct_alloc_fail);
- FF_ALLOC_OR_GOTO(mdct->avctx, mdct->cplx_tmp, n4 * sizeof(*mdct->cplx_tmp),
- mdct_alloc_fail);
+ mdct->window = ff_ac3_window;
+
+ FF_ALLOC_OR_GOTO(avctx, mdct->xcos1, n4 * sizeof(*mdct->xcos1), mdct_alloc_fail);
+ FF_ALLOC_OR_GOTO(avctx, mdct->xsin1, n4 * sizeof(*mdct->xsin1), mdct_alloc_fail);
+ FF_ALLOC_OR_GOTO(avctx, mdct->rot_tmp, n * sizeof(*mdct->rot_tmp), mdct_alloc_fail);
+ FF_ALLOC_OR_GOTO(avctx, mdct->cplx_tmp, n4 * sizeof(*mdct->cplx_tmp), mdct_alloc_fail);
for (i = 0; i < n4; i++) {
float alpha = 2.0 * M_PI * (i + 1.0 / 8.0) / n;
for (ch = 0; ch < s->channels; ch++) {
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
AC3Block *block = &s->blocks[blk];
- const int16_t *input_samples = &s->planar_samples[ch][blk * AC3_BLOCK_SIZE];
+ const SampleType *input_samples = &s->planar_samples[ch][blk * AC3_BLOCK_SIZE];
- apply_window(s->windowed_samples, input_samples, ff_ac3_window, AC3_WINDOW_SIZE);
+ apply_window(s->windowed_samples, input_samples, s->mdct.window, AC3_WINDOW_SIZE);
block->exp_shift[ch] = normalize_samples(s);
AC3Block *block = &s->blocks[blk];
for (i = 0; i < AC3_MAX_COEFS; i++) {
int e;
- int v = abs(block->mdct_coef[ch][i]);
+ int v = abs(SCALE_COEF(block->mdct_coef[ch][i]));
if (v == 0)
e = 24;
else {
/**
* Calculate exponent strategies for all blocks in a single channel.
*/
-static void compute_exp_strategy_ch(AC3EncodeContext *s, uint8_t *exp_strategy, uint8_t **exp)
+static void compute_exp_strategy_ch(AC3EncodeContext *s, uint8_t *exp_strategy,
+ uint8_t **exp)
{
int blk, blk1;
int exp_diff;
/**
* Update the exponents so that they are the ones the decoder will decode.
*/
-static void encode_exponents_blk_ch(uint8_t *exp,
- int nb_exps, int exp_strategy)
+static void encode_exponents_blk_ch(uint8_t *exp, int nb_exps, int exp_strategy)
{
int nb_groups, i, k;
s->slow_decay_code = 2;
s->fast_decay_code = 1;
s->slow_gain_code = 1;
- s->db_per_bit_code = 2;
+ s->db_per_bit_code = 3;
s->floor_code = 4;
for (ch = 0; ch < s->channels; ch++)
s->fast_gain_code[ch] = 4;
* @return the number of bits needed for mantissas if the given SNR offset is
* is used.
*/
-static int bit_alloc(AC3EncodeContext *s,
- int snr_offset)
+static int bit_alloc(AC3EncodeContext *s, int snr_offset)
{
int blk, ch;
int mantissa_bits;
/**
* Quantize a set of mantissas for a single channel in a single block.
*/
-static void quantize_mantissas_blk_ch(AC3EncodeContext *s,
- int32_t *mdct_coef, int8_t exp_shift,
- uint8_t *exp, uint8_t *bap,
- uint16_t *qmant, int n)
+static void quantize_mantissas_blk_ch(AC3EncodeContext *s, CoefType *mdct_coef,
+ int8_t exp_shift, uint8_t *exp,
+ uint8_t *bap, uint16_t *qmant, int n)
{
int i;
for (i = 0; i < n; i++) {
int v;
- int c = mdct_coef[i];
+ int c = SCALE_COEF(mdct_coef[i]);
int e = exp[i] - exp_shift;
int b = bap[i];
switch (b) {
/**
* Write one audio block to the output bitstream.
*/
-static void output_audio_block(AC3EncodeContext *s,
- int block_num)
+static void output_audio_block(AC3EncodeContext *s, int block_num)
{
int ch, i, baie, rbnd;
AC3Block *block = &s->blocks[block_num];
/**
* Write the frame to the output bitstream.
*/
-static void output_frame(AC3EncodeContext *s,
- unsigned char *frame)
+static void output_frame(AC3EncodeContext *s, unsigned char *frame)
{
int blk;
/**
* Encode a single AC-3 frame.
*/
-static int ac3_encode_frame(AVCodecContext *avctx,
- unsigned char *frame, int buf_size, void *data)
+static int ac3_encode_frame(AVCodecContext *avctx, unsigned char *frame,
+ int buf_size, void *data)
{
AC3EncodeContext *s = avctx->priv_data;
- const int16_t *samples = data;
+ const SampleType *samples = data;
int ret;
if (s->bit_alloc.sr_code == 1)
bit_alloc_init(s);
- s->mdct.avctx = avctx;
- ret = mdct_init(&s->mdct, 9);
+ ret = mdct_init(avctx, &s->mdct, 9);
if (ret)
goto init_fail;
NULL,
.sample_fmts = (const enum AVSampleFormat[]){AV_SAMPLE_FMT_S16,AV_SAMPLE_FMT_NONE},
.long_name = NULL_IF_CONFIG_SMALL("ATSC A/52A (AC-3)"),
- .channel_layouts = (const int64_t[]){
- AV_CH_LAYOUT_MONO,
- AV_CH_LAYOUT_STEREO,
- AV_CH_LAYOUT_2_1,
- AV_CH_LAYOUT_SURROUND,
- AV_CH_LAYOUT_2_2,
- AV_CH_LAYOUT_QUAD,
- AV_CH_LAYOUT_4POINT0,
- AV_CH_LAYOUT_5POINT0,
- AV_CH_LAYOUT_5POINT0_BACK,
- (AV_CH_LAYOUT_MONO | AV_CH_LOW_FREQUENCY),
- (AV_CH_LAYOUT_STEREO | AV_CH_LOW_FREQUENCY),
- (AV_CH_LAYOUT_2_1 | AV_CH_LOW_FREQUENCY),
- (AV_CH_LAYOUT_SURROUND | AV_CH_LOW_FREQUENCY),
- (AV_CH_LAYOUT_2_2 | AV_CH_LOW_FREQUENCY),
- (AV_CH_LAYOUT_QUAD | AV_CH_LOW_FREQUENCY),
- (AV_CH_LAYOUT_4POINT0 | AV_CH_LOW_FREQUENCY),
- AV_CH_LAYOUT_5POINT1,
- AV_CH_LAYOUT_5POINT1_BACK,
- 0 },
+ .channel_layouts = ac3_channel_layouts,
};
projects / ffmpeg / blobdiff