/**
* FLAC audio encoder
- * Copyright (c) 2006 Justin Ruggles <jruggle@earthlink.net>
+ * Copyright (c) 2006 Justin Ruggles <justin.ruggles@gmail.com>
*
* This file is part of FFmpeg.
*
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
+#include "libavutil/crc.h"
+#include "libavutil/lls.h"
#include "avcodec.h"
#include "bitstream.h"
-#include "crc.h"
+#include "dsputil.h"
#include "golomb.h"
-#include "lls.h"
+#include "lpc.h"
#define FLAC_MAX_CH 8
#define FLAC_MIN_BLOCKSIZE 16
#define FLAC_CHMODE_RIGHT_SIDE 9
#define FLAC_CHMODE_MID_SIDE 10
-#define ORDER_METHOD_EST 0
-#define ORDER_METHOD_2LEVEL 1
-#define ORDER_METHOD_4LEVEL 2
-#define ORDER_METHOD_8LEVEL 3
-#define ORDER_METHOD_SEARCH 4
-#define ORDER_METHOD_LOG 5
-
#define FLAC_STREAMINFO_SIZE 34
-#define MIN_LPC_ORDER 1
-#define MAX_LPC_ORDER 32
#define MAX_FIXED_ORDER 4
#define MAX_PARTITION_ORDER 8
#define MAX_PARTITIONS (1 << MAX_PARTITION_ORDER)
int shift;
RiceContext rc;
int32_t samples[FLAC_MAX_BLOCKSIZE];
- int32_t residual[FLAC_MAX_BLOCKSIZE];
+ int32_t residual[FLAC_MAX_BLOCKSIZE+1];
} FlacSubframe;
typedef struct FlacFrame {
int ch_code;
int samplerate;
int sr_code[2];
- int blocksize;
int max_framesize;
uint32_t frame_count;
FlacFrame frame;
CompressionOptions options;
AVCodecContext *avctx;
+ DSPContext dsp;
} FlacEncodeContext;
static const int flac_samplerates[16] = {
init_put_bits(&pb, header, FLAC_STREAMINFO_SIZE);
/* streaminfo metadata block */
- put_bits(&pb, 16, s->blocksize);
- put_bits(&pb, 16, s->blocksize);
+ put_bits(&pb, 16, s->avctx->frame_size);
+ put_bits(&pb, 16, s->avctx->frame_size);
put_bits(&pb, 24, 0);
put_bits(&pb, 24, s->max_framesize);
put_bits(&pb, 20, s->samplerate);
return blocksize;
}
-static int flac_encode_init(AVCodecContext *avctx)
+static av_cold int flac_encode_init(AVCodecContext *avctx)
{
int freq = avctx->sample_rate;
int channels = avctx->channels;
s->avctx = avctx;
+ dsputil_init(&s->dsp, avctx);
+
if(avctx->sample_fmt != SAMPLE_FMT_S16) {
return -1;
}
avctx->frame_size);
return -1;
}
- s->blocksize = avctx->frame_size;
} else {
- s->blocksize = select_blocksize(s->samplerate, s->options.block_time_ms);
- avctx->frame_size = s->blocksize;
+ s->avctx->frame_size = select_blocksize(s->samplerate, s->options.block_time_ms);
}
- av_log(avctx, AV_LOG_DEBUG, " block size: %d\n", s->blocksize);
+ av_log(avctx, AV_LOG_DEBUG, " block size: %d\n", s->avctx->frame_size);
/* set LPC precision */
if(avctx->lpc_coeff_precision > 0) {
}
s->options.lpc_coeff_precision = avctx->lpc_coeff_precision;
} else {
- /* select LPC precision based on block size */
- if( s->blocksize <= 192) s->options.lpc_coeff_precision = 7;
- else if(s->blocksize <= 384) s->options.lpc_coeff_precision = 8;
- else if(s->blocksize <= 576) s->options.lpc_coeff_precision = 9;
- else if(s->blocksize <= 1152) s->options.lpc_coeff_precision = 10;
- else if(s->blocksize <= 2304) s->options.lpc_coeff_precision = 11;
- else if(s->blocksize <= 4608) s->options.lpc_coeff_precision = 12;
- else if(s->blocksize <= 8192) s->options.lpc_coeff_precision = 13;
- else if(s->blocksize <= 16384) s->options.lpc_coeff_precision = 14;
- else s->options.lpc_coeff_precision = 15;
+ /* default LPC precision */
+ s->options.lpc_coeff_precision = 15;
}
av_log(avctx, AV_LOG_DEBUG, " lpc precision: %d\n",
s->options.lpc_coeff_precision);
/* set maximum encoded frame size in verbatim mode */
if(s->channels == 2) {
- s->max_framesize = 14 + ((s->blocksize * 33 + 7) >> 3);
+ s->max_framesize = 14 + ((s->avctx->frame_size * 33 + 7) >> 3);
} else {
- s->max_framesize = 14 + (s->blocksize * s->channels * 2);
+ s->max_framesize = 14 + (s->avctx->frame_size * s->channels * 2);
}
streaminfo = av_malloc(FLAC_STREAMINFO_SIZE);
frame = &s->frame;
for(i=0; i<16; i++) {
- if(s->blocksize == flac_blocksizes[i]) {
+ if(s->avctx->frame_size == flac_blocksizes[i]) {
frame->blocksize = flac_blocksizes[i];
frame->bs_code[0] = i;
frame->bs_code[1] = 0;
}
}
if(i == 16) {
- frame->blocksize = s->blocksize;
+ frame->blocksize = s->avctx->frame_size;
if(frame->blocksize <= 256) {
frame->bs_code[0] = 6;
frame->bs_code[1] = frame->blocksize-1;
#define rice_encode_count(sum, n, k) (((n)*((k)+1))+((sum-(n>>1))>>(k)))
+/**
+ * Solve for d/dk(rice_encode_count) = n-((sum-(n>>1))>>(k+1)) = 0
+ */
static int find_optimal_param(uint32_t sum, int n)
{
- int k, k_opt;
- uint32_t nbits[MAX_RICE_PARAM+1];
-
- k_opt = 0;
- nbits[0] = UINT32_MAX;
- for(k=0; k<=MAX_RICE_PARAM; k++) {
- nbits[k] = rice_encode_count(sum, n, k);
- if(nbits[k] < nbits[k_opt]) {
- k_opt = k;
- }
- }
- return k_opt;
+ int k;
+ uint32_t sum2;
+
+ if(sum <= n>>1)
+ return 0;
+ sum2 = sum-(n>>1);
+ k = av_log2(n<256 ? FASTDIV(sum2,n) : sum2/n);
+ return FFMIN(k, MAX_RICE_PARAM);
}
static uint32_t calc_optimal_rice_params(RiceContext *rc, int porder,
uint32_t all_bits;
part = (1 << porder);
- all_bits = 0;
+ all_bits = 4 * part;
cnt = (n >> porder) - pred_order;
for(i=0; i<part; i++) {
- if(i == 1) cnt = (n >> porder);
k = find_optimal_param(sums[i], cnt);
rc->params[i] = k;
all_bits += rice_encode_count(sums[i], cnt, k);
+ cnt = n >> porder;
}
- all_bits += (4 * part);
rc->porder = porder;
res = &data[pred_order];
res_end = &data[n >> pmax];
for(i=0; i<parts; i++) {
- sums[pmax][i] = 0;
+ uint32_t sum = 0;
while(res < res_end){
- sums[pmax][i] += *(res++);
+ sum += *(res++);
}
+ sums[pmax][i] = sum;
res_end+= n >> pmax;
}
/* sums for lower levels */
double w;
double c;
+ assert(!(len&1)); //the optimization in r11881 does not support odd len
+ //if someone wants odd len extend the change in r11881
+
n2 = (len >> 1);
c = 2.0 / (len - 1.0);
+
+ w_data+=n2;
+ data+=n2;
for(i=0; i<n2; i++) {
- w = c - i - 1.0;
+ w = c - n2 + i;
w = 1.0 - (w * w);
- w_data[i] = data[i] * w;
- w_data[len-1-i] = data[len-1-i] * w;
+ w_data[-i-1] = data[-i-1] * w;
+ w_data[+i ] = data[+i ] * w;
}
}
* Calculates autocorrelation data from audio samples
* A Welch window function is applied before calculation.
*/
-static void compute_autocorr(const int32_t *data, int len, int lag,
- double *autoc)
+void ff_flac_compute_autocorr(const int32_t *data, int len, int lag,
+ double *autoc)
{
- int i, lag_ptr;
- double tmp[len + lag];
+ int i, j;
+ double tmp[len + lag + 1];
double *data1= tmp + lag;
apply_welch_window(data, len, data1);
- for(i=0; i<lag; i++){
- autoc[i] = 1.0;
- data1[i-lag]= 0.0;
- }
-
- for(i=0; i<len; i++){
- for(lag_ptr= i-lag; lag_ptr<=i; lag_ptr++){
- autoc[i-lag_ptr] += data1[i] * data1[lag_ptr];
- }
- }
-}
-
-/**
- * Levinson-Durbin recursion.
- * Produces LPC coefficients from autocorrelation data.
- */
-static void compute_lpc_coefs(const double *autoc, int max_order,
- double lpc[][MAX_LPC_ORDER], double *ref)
-{
- int i, j, i2;
- double r, err, tmp;
- double lpc_tmp[MAX_LPC_ORDER];
-
- for(i=0; i<max_order; i++) lpc_tmp[i] = 0;
- err = autoc[0];
-
- for(i=0; i<max_order; i++) {
- r = -autoc[i+1];
- for(j=0; j<i; j++) {
- r -= lpc_tmp[j] * autoc[i-j];
- }
- r /= err;
- ref[i] = fabs(r);
-
- err *= 1.0 - (r * r);
-
- i2 = (i >> 1);
- lpc_tmp[i] = r;
- for(j=0; j<i2; j++) {
- tmp = lpc_tmp[j];
- lpc_tmp[j] += r * lpc_tmp[i-1-j];
- lpc_tmp[i-1-j] += r * tmp;
- }
- if(i & 1) {
- lpc_tmp[j] += lpc_tmp[j] * r;
- }
-
- for(j=0; j<=i; j++) {
- lpc[i][j] = -lpc_tmp[j];
- }
- }
-}
-
-/**
- * Quantize LPC coefficients
- */
-static void quantize_lpc_coefs(double *lpc_in, int order, int precision,
- int32_t *lpc_out, int *shift)
-{
- int i;
- double cmax, error;
- int32_t qmax;
- int sh;
-
- /* define maximum levels */
- qmax = (1 << (precision - 1)) - 1;
+ for(j=0; j<lag; j++)
+ data1[j-lag]= 0.0;
+ data1[len] = 0.0;
- /* find maximum coefficient value */
- cmax = 0.0;
- for(i=0; i<order; i++) {
- cmax= FFMAX(cmax, fabs(lpc_in[i]));
- }
-
- /* if maximum value quantizes to zero, return all zeros */
- if(cmax * (1 << MAX_LPC_SHIFT) < 1.0) {
- *shift = 0;
- memset(lpc_out, 0, sizeof(int32_t) * order);
- return;
- }
-
- /* calculate level shift which scales max coeff to available bits */
- sh = MAX_LPC_SHIFT;
- while((cmax * (1 << sh) > qmax) && (sh > 0)) {
- sh--;
- }
-
- /* since negative shift values are unsupported in decoder, scale down
- coefficients instead */
- if(sh == 0 && cmax > qmax) {
- double scale = ((double)qmax) / cmax;
- for(i=0; i<order; i++) {
- lpc_in[i] *= scale;
+ for(j=0; j<lag; j+=2){
+ double sum0 = 1.0, sum1 = 1.0;
+ for(i=0; i<len; i++){
+ sum0 += data1[i] * data1[i-j];
+ sum1 += data1[i] * data1[i-j-1];
}
+ autoc[j ] = sum0;
+ autoc[j+1] = sum1;
}
- /* output quantized coefficients and level shift */
- error=0;
- for(i=0; i<order; i++) {
- error += lpc_in[i] * (1 << sh);
- lpc_out[i] = av_clip(lrintf(error), -qmax, qmax);
- error -= lpc_out[i];
- }
- *shift = sh;
-}
-
-static int estimate_best_order(double *ref, int max_order)
-{
- int i, est;
-
- est = 1;
- for(i=max_order-1; i>=0; i--) {
- if(ref[i] > 0.10) {
- est = i+1;
- break;
+ if(j==lag){
+ double sum = 1.0;
+ for(i=0; i<len; i+=2){
+ sum += data1[i ] * data1[i-j ]
+ + data1[i+1] * data1[i-j+1];
}
+ autoc[j] = sum;
}
- return est;
-}
-
-/**
- * Calculate LPC coefficients for multiple orders
- */
-static int lpc_calc_coefs(const int32_t *samples, int blocksize, int max_order,
- int precision, int32_t coefs[][MAX_LPC_ORDER],
- int *shift, int use_lpc, int omethod)
-{
- double autoc[MAX_LPC_ORDER+1];
- double ref[MAX_LPC_ORDER];
- double lpc[MAX_LPC_ORDER][MAX_LPC_ORDER];
- int i, j, pass;
- int opt_order;
-
- assert(max_order >= MIN_LPC_ORDER && max_order <= MAX_LPC_ORDER);
-
- if(use_lpc == 1){
- compute_autocorr(samples, blocksize, max_order+1, autoc);
-
- compute_lpc_coefs(autoc, max_order, lpc, ref);
- }else{
- LLSModel m[2];
- double var[MAX_LPC_ORDER+1], eval, weight;
-
- for(pass=0; pass<use_lpc-1; pass++){
- av_init_lls(&m[pass&1], max_order);
-
- weight=0;
- for(i=max_order; i<blocksize; i++){
- for(j=0; j<=max_order; j++)
- var[j]= samples[i-j];
-
- if(pass){
- eval= av_evaluate_lls(&m[(pass-1)&1], var+1, max_order-1);
- eval= (512>>pass) + fabs(eval - var[0]);
- for(j=0; j<=max_order; j++)
- var[j]/= sqrt(eval);
- weight += 1/eval;
- }else
- weight++;
-
- av_update_lls(&m[pass&1], var, 1.0);
- }
- av_solve_lls(&m[pass&1], 0.001, 0);
- }
-
- for(i=0; i<max_order; i++){
- for(j=0; j<max_order; j++)
- lpc[i][j]= m[(pass-1)&1].coeff[i][j];
- ref[i]= sqrt(m[(pass-1)&1].variance[i] / weight) * (blocksize - max_order) / 4000;
- }
- for(i=max_order-1; i>0; i--)
- ref[i] = ref[i-1] - ref[i];
- }
- opt_order = max_order;
-
- if(omethod == ORDER_METHOD_EST) {
- opt_order = estimate_best_order(ref, max_order);
- i = opt_order-1;
- quantize_lpc_coefs(lpc[i], i+1, precision, coefs[i], &shift[i]);
- } else {
- for(i=0; i<max_order; i++) {
- quantize_lpc_coefs(lpc[i], i+1, precision, coefs[i], &shift[i]);
- }
- }
-
- return opt_order;
}
for(i=order; i<n; i++)
res[i]= smp[i] - smp[i-1];
}else if(order==2){
- for(i=order; i<n; i++)
- res[i]= smp[i] - 2*smp[i-1] + smp[i-2];
+ int a = smp[order-1] - smp[order-2];
+ for(i=order; i<n; i+=2) {
+ int b = smp[i] - smp[i-1];
+ res[i]= b - a;
+ a = smp[i+1] - smp[i];
+ res[i+1]= a - b;
+ }
}else if(order==3){
- for(i=order; i<n; i++)
- res[i]= smp[i] - 3*smp[i-1] + 3*smp[i-2] - smp[i-3];
+ int a = smp[order-1] - smp[order-2];
+ int c = smp[order-1] - 2*smp[order-2] + smp[order-3];
+ for(i=order; i<n; i+=2) {
+ int b = smp[i] - smp[i-1];
+ int d = b - a;
+ res[i]= d - c;
+ a = smp[i+1] - smp[i];
+ c = a - b;
+ res[i+1]= c - d;
+ }
}else{
- for(i=order; i<n; i++)
- res[i]= smp[i] - 4*smp[i-1] + 6*smp[i-2] - 4*smp[i-3] + smp[i-4];
+ int a = smp[order-1] - smp[order-2];
+ int c = smp[order-1] - 2*smp[order-2] + smp[order-3];
+ int e = smp[order-1] - 3*smp[order-2] + 3*smp[order-3] - smp[order-4];
+ for(i=order; i<n; i+=2) {
+ int b = smp[i] - smp[i-1];
+ int d = b - a;
+ int f = d - c;
+ res[i]= f - e;
+ a = smp[i+1] - smp[i];
+ c = a - b;
+ e = c - d;
+ res[i+1]= e - f;
+ }
+ }
+}
+
+#define LPC1(x) {\
+ int c = coefs[(x)-1];\
+ p0 += c*s;\
+ s = smp[i-(x)+1];\
+ p1 += c*s;\
+}
+
+static av_always_inline void encode_residual_lpc_unrolled(
+ int32_t *res, const int32_t *smp, int n,
+ int order, const int32_t *coefs, int shift, int big)
+{
+ int i;
+ for(i=order; i<n; i+=2) {
+ int s = smp[i-order];
+ int p0 = 0, p1 = 0;
+ if(big) {
+ switch(order) {
+ case 32: LPC1(32)
+ case 31: LPC1(31)
+ case 30: LPC1(30)
+ case 29: LPC1(29)
+ case 28: LPC1(28)
+ case 27: LPC1(27)
+ case 26: LPC1(26)
+ case 25: LPC1(25)
+ case 24: LPC1(24)
+ case 23: LPC1(23)
+ case 22: LPC1(22)
+ case 21: LPC1(21)
+ case 20: LPC1(20)
+ case 19: LPC1(19)
+ case 18: LPC1(18)
+ case 17: LPC1(17)
+ case 16: LPC1(16)
+ case 15: LPC1(15)
+ case 14: LPC1(14)
+ case 13: LPC1(13)
+ case 12: LPC1(12)
+ case 11: LPC1(11)
+ case 10: LPC1(10)
+ case 9: LPC1( 9)
+ LPC1( 8)
+ LPC1( 7)
+ LPC1( 6)
+ LPC1( 5)
+ LPC1( 4)
+ LPC1( 3)
+ LPC1( 2)
+ LPC1( 1)
+ }
+ } else {
+ switch(order) {
+ case 8: LPC1( 8)
+ case 7: LPC1( 7)
+ case 6: LPC1( 6)
+ case 5: LPC1( 5)
+ case 4: LPC1( 4)
+ case 3: LPC1( 3)
+ case 2: LPC1( 2)
+ case 1: LPC1( 1)
+ }
+ }
+ res[i ] = smp[i ] - (p0 >> shift);
+ res[i+1] = smp[i+1] - (p1 >> shift);
}
}
static void encode_residual_lpc(int32_t *res, const int32_t *smp, int n,
int order, const int32_t *coefs, int shift)
{
- int i, j;
-
+ int i;
for(i=0; i<order; i++) {
res[i] = smp[i];
}
+#ifdef CONFIG_SMALL
for(i=order; i<n; i+=2) {
- int32_t c = coefs[0];
- int32_t p0 = 0, p1 = c*smp[i];
- for(j=1; j<order; j++) {
- int32_t s = smp[i-j];
- p0 += c*s;
- c = coefs[j];
+ int j;
+ int s = smp[i];
+ int p0 = 0, p1 = 0;
+ for(j=0; j<order; j++) {
+ int c = coefs[j];
p1 += c*s;
+ s = smp[i-j-1];
+ p0 += c*s;
}
- p0 += c*smp[i-order];
- res[i+0] = smp[i+0] - (p0 >> shift);
+ res[i ] = smp[i ] - (p0 >> shift);
res[i+1] = smp[i+1] - (p1 >> shift);
}
+#else
+ switch(order) {
+ case 1: encode_residual_lpc_unrolled(res, smp, n, 1, coefs, shift, 0); break;
+ case 2: encode_residual_lpc_unrolled(res, smp, n, 2, coefs, shift, 0); break;
+ case 3: encode_residual_lpc_unrolled(res, smp, n, 3, coefs, shift, 0); break;
+ case 4: encode_residual_lpc_unrolled(res, smp, n, 4, coefs, shift, 0); break;
+ case 5: encode_residual_lpc_unrolled(res, smp, n, 5, coefs, shift, 0); break;
+ case 6: encode_residual_lpc_unrolled(res, smp, n, 6, coefs, shift, 0); break;
+ case 7: encode_residual_lpc_unrolled(res, smp, n, 7, coefs, shift, 0); break;
+ case 8: encode_residual_lpc_unrolled(res, smp, n, 8, coefs, shift, 0); break;
+ default: encode_residual_lpc_unrolled(res, smp, n, order, coefs, shift, 1); break;
+ }
+#endif
}
static int encode_residual(FlacEncodeContext *ctx, int ch)
}
/* LPC */
- opt_order = lpc_calc_coefs(smp, n, max_order, precision, coefs, shift, ctx->options.use_lpc, omethod);
+ opt_order = ff_lpc_calc_coefs(&ctx->dsp, smp, n, min_order, max_order,
+ precision, coefs, shift, ctx->options.use_lpc,
+ omethod, MAX_LPC_SHIFT, 0);
if(omethod == ORDER_METHOD_2LEVEL ||
omethod == ORDER_METHOD_4LEVEL ||
}
}
-static void put_sbits(PutBitContext *pb, int bits, int32_t val)
-{
- assert(bits >= 0 && bits <= 31);
-
- put_bits(pb, bits, val & ((1<<bits)-1));
-}
-
static void write_utf8(PutBitContext *pb, uint32_t val)
{
uint8_t tmp;
put_bits(&s->pb, 16, s->sr_code[1]);
}
flush_put_bits(&s->pb);
- crc = av_crc(av_crc07, 0, s->pb.buf, put_bits_count(&s->pb)>>3);
+ crc = av_crc(av_crc_get_table(AV_CRC_8_ATM), 0,
+ s->pb.buf, put_bits_count(&s->pb)>>3);
put_bits(&s->pb, 8, crc);
}
{
int crc;
flush_put_bits(&s->pb);
- crc = bswap_16(av_crc(av_crc8005, 0, s->pb.buf, put_bits_count(&s->pb)>>3));
+ crc = bswap_16(av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0,
+ s->pb.buf, put_bits_count(&s->pb)>>3));
put_bits(&s->pb, 16, crc);
flush_put_bits(&s->pb);
}
FlacEncodeContext *s;
int16_t *samples = data;
int out_bytes;
+ int reencoded=0;
s = avctx->priv_data;
- s->blocksize = avctx->frame_size;
+ if(buf_size < s->max_framesize*2) {
+ av_log(avctx, AV_LOG_ERROR, "output buffer too small\n");
+ return 0;
+ }
+
init_frame(s);
copy_samples(s, samples);
for(ch=0; ch<s->channels; ch++) {
encode_residual(s, ch);
}
+
+write_frame:
init_put_bits(&s->pb, frame, buf_size);
output_frame_header(s);
output_subframes(s);
output_frame_footer(s);
out_bytes = put_bits_count(&s->pb) >> 3;
- if(out_bytes > s->max_framesize || out_bytes >= buf_size) {
- /* frame too large. use verbatim mode */
- for(ch=0; ch<s->channels; ch++) {
- encode_residual_v(s, ch);
- }
- init_put_bits(&s->pb, frame, buf_size);
- output_frame_header(s);
- output_subframes(s);
- output_frame_footer(s);
- out_bytes = put_bits_count(&s->pb) >> 3;
-
- if(out_bytes > s->max_framesize || out_bytes >= buf_size) {
+ if(out_bytes > s->max_framesize) {
+ if(reencoded) {
/* still too large. must be an error. */
av_log(avctx, AV_LOG_ERROR, "error encoding frame\n");
return -1;
}
+
+ /* frame too large. use verbatim mode */
+ for(ch=0; ch<s->channels; ch++) {
+ encode_residual_v(s, ch);
+ }
+ reencoded = 1;
+ goto write_frame;
}
s->frame_count++;
return out_bytes;
}
-static int flac_encode_close(AVCodecContext *avctx)
+static av_cold int flac_encode_close(AVCodecContext *avctx)
{
av_freep(&avctx->extradata);
avctx->extradata_size = 0;
flac_encode_close,
NULL,
.capabilities = CODEC_CAP_SMALL_LAST_FRAME,
+ .sample_fmts = (enum SampleFormat[]){SAMPLE_FMT_S16,SAMPLE_FMT_NONE},
+ .long_name = NULL_IF_CONFIG_SMALL("FLAC (Free Lossless Audio Codec)"),
};