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FFmpeg/libavcodec/vorbis.c

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Vorbis decoder by (Balatoni Denes | dbalatoni programozo hu) Originally committed as revision 4261 to svn://svn.ffmpeg.org/ffmpeg/trunk
20 years ago
/**
* @file vorbis.c
* Vorbis I decoder
* @author Denes Balatoni ( dbalatoni programozo hu )
*/
#undef V_DEBUG
#include <math.h>
#define ALT_BITSTREAM_READER_LE
#include "avcodec.h"
#include "bitstream.h"
#include "dsputil.h"
#include "vorbis.h"
#define V_NB_BITS 11
#define V_MAX_VLCS (1<<16)
#ifndef V_DEBUG
#define AV_DEBUG(...)
#endif
/* Helper functions */
/**
* reads 0-32 bits when using the ALT_BITSTREAM_READER_LE bitstream reader
*/
unsigned int get_bits_long_le(GetBitContext *s, int n){
if(n<=17) return get_bits(s, n);
else{
int ret= get_bits(s, 16);
return ret | (get_bits(s, n-16) << 16);
}
}
static unsigned int ilog(unsigned int i) { // unfortunatelly av_log2 uses different rounding
unsigned int ret=0;
while (i!=0) {
++ret;
i>>=1;
}
return ret;
}
static unsigned int nth_root(unsigned int x, unsigned int n) { // x^(1/n)
unsigned int ret=0, i, j;
do {
++ret;
for(i=0,j=ret;i<n-1;i++) j*=ret;
} while (j<=x);
return (ret-1);
}
static float vorbisfloat2float(uint_fast32_t val) {
double mant=val&0x1fffff;
long exp=(val&0x7fe00000L)>>21;
if (val&0x80000000) mant=-mant;
return(ldexp(mant, exp-20-768));
}
// Generate vlc codes from vorbis huffman code lengths
static int vorbis_len2vlc(vorbis_context *vc, uint_fast8_t *bits, uint_fast32_t *codes, uint_fast32_t num) {
uint_fast32_t exit_at_level[33]={404,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
uint_fast8_t i,j;
uint_fast32_t code,p;
#ifdef V_DEBUG
GetBitContext gb;
#endif
for(p=0;(bits[p]==0) && (p<num);++p);
if (p==num) {
// av_log(vc->avccontext, AV_LOG_INFO, "An empty codebook. Heh?! \n");
return 0;
}
codes[p]=0;
for(i=0;i<bits[p];++i) {
exit_at_level[i+1]=1<<i;
}
#ifdef V_DEBUG
av_log(vc->avccontext, AV_LOG_INFO, " %d. of %d code len %d code %d - ", p, num, bits[p], codes[p]);
init_get_bits(&gb, (uint_fast8_t *)&codes[p], bits[p]);
for(i=0;i<bits[p];++i) {
av_log(vc->avccontext, AV_LOG_INFO, "%s", get_bits1(&gb) ? "1" : "0");
}
av_log(vc->avccontext, AV_LOG_INFO, "\n");
#endif
++p;
for(;p<num;++p) {
if (bits[p]==0) continue;
// find corresponding exit(node which the tree can grow further from)
for(i=bits[p];i>0;--i) {
if (exit_at_level[i]) break;
}
if (!i) return 1; // overspecified tree
code=exit_at_level[i];
exit_at_level[i]=0;
// construct code (append 0s to end) and introduce new exits
for(j=i+1;j<=bits[p];++j) {
exit_at_level[j]=code+(1<<(j-1));
}
codes[p]=code;
#ifdef V_DEBUG
av_log(vc->avccontext, AV_LOG_INFO, " %d. code len %d code %d - ", p, bits[p], codes[p]);
init_get_bits(&gb, (uint_fast8_t *)&codes[p], bits[p]);
for(i=0;i<bits[p];++i) {
av_log(vc->avccontext, AV_LOG_INFO, "%s", get_bits1(&gb) ? "1" : "0");
}
av_log(vc->avccontext, AV_LOG_INFO, "\n");
#endif
}
//FIXME no exits should be left (underspecified tree - ie. unused valid vlcs - not allowed by SPEC)
return 0;
}
// Free all allocated memory -----------------------------------------
static void vorbis_free(vorbis_context *vc) {
int_fast16_t i;
av_freep(&vc->channel_residues);
av_freep(&vc->channel_floors);
av_freep(&vc->saved);
av_freep(&vc->ret);
av_freep(&vc->residues);
av_freep(&vc->modes);
ff_mdct_end(&vc->mdct0);
ff_mdct_end(&vc->mdct1);
for(i=0;i<vc->codebook_count;++i) {
av_free(vc->codebooks[i].codevectors);
free_vlc(&vc->codebooks[i].vlc);
}
av_freep(&vc->codebooks);
for(i=0;i<vc->floor_count;++i) {
av_free(vc->floors[i].x_list);
av_free(vc->floors[i].x_list_order);
av_free(vc->floors[i].low_neighbour);
av_free(vc->floors[i].high_neighbour);
}
av_freep(&vc->floors);
for(i=0;i<vc->mapping_count;++i) {
av_free(vc->mappings[i].magnitude);
av_free(vc->mappings[i].angle);
av_free(vc->mappings[i].mux);
}
av_freep(&vc->mappings);
}
// Parse setup header -------------------------------------------------
// Process codebooks part
static int vorbis_parse_setup_hdr_codebooks(vorbis_context *vc) {
uint_fast16_t cb;
GetBitContext *gb=&vc->gb;
vc->codebook_count=get_bits(gb,8)+1;
AV_DEBUG(" Codebooks: %d \n", vc->codebook_count);
vc->codebooks=(vorbis_codebook *)av_mallocz(vc->codebook_count * sizeof(vorbis_codebook));
for(cb=0;cb<vc->codebook_count;++cb) {
vorbis_codebook *codebook_setup=&vc->codebooks[cb];
uint_fast8_t ordered;
uint_fast32_t t, used_entries=0;
uint_fast32_t entries;
uint_fast8_t tmp_vlc_bits[V_MAX_VLCS];
uint_fast32_t tmp_vlc_codes[V_MAX_VLCS];
// memset(tmp_vlc_bits, 0, sizeof(tmp_vlc_bits));
AV_DEBUG(" %d. Codebook \n", cb);
if (get_bits(gb, 24)!=0x564342) {
av_log(vc->avccontext, AV_LOG_ERROR, " %d. Codebook setup data corrupt. \n", cb);
return 1;
}
codebook_setup->dimensions=get_bits(gb, 16);
if (codebook_setup->dimensions>16) {
av_log(vc->avccontext, AV_LOG_ERROR, " %d. Codebook's dimension is too large (%d). \n", cb, codebook_setup->dimensions);
return 1;
}
entries=get_bits(gb, 24);
if (entries>V_MAX_VLCS) {
av_log(vc->avccontext, AV_LOG_ERROR, " %d. Codebook has too many entries (%d). \n", cb, entries);
return 1;
}
ordered=get_bits1(gb);
AV_DEBUG(" codebook_dimensions %d, codebook_entries %d \n", codebook_setup->dimensions, entries);
if (!ordered) {
uint_fast16_t ce;
uint_fast8_t flag;
uint_fast8_t sparse=get_bits1(gb);
AV_DEBUG(" not ordered \n");
if (sparse) {
AV_DEBUG(" sparse \n");
used_entries=0;
for(ce=0;ce<entries;++ce) {
flag=get_bits1(gb);
if (flag) {
tmp_vlc_bits[ce]=get_bits(gb, 5)+1;
++used_entries;
}
else tmp_vlc_bits[ce]=0;
}
} else {
AV_DEBUG(" not sparse \n");
used_entries=entries;
for(ce=0;ce<entries;++ce) {
tmp_vlc_bits[ce]=get_bits(gb, 5)+1;
}
}
} else {
uint_fast16_t current_entry=0;
uint_fast8_t current_length=get_bits(gb, 5)+1;
AV_DEBUG(" ordered, current length: %d \n", current_length); //FIXME
used_entries=entries;
for(;current_entry<used_entries;++current_length) {
uint_fast16_t i, number;
AV_DEBUG(" number bits: %d ", ilog(entries - current_entry));
number=get_bits(gb, ilog(entries - current_entry));
AV_DEBUG(" number: %d \n", number);
for(i=current_entry;i<number+current_entry;++i) {
if (i<used_entries) tmp_vlc_bits[i]=current_length;
}
current_entry+=number;
}
if (current_entry>used_entries) {
av_log(vc->avccontext, AV_LOG_ERROR, " More codelengths than codes in codebook. \n");
return 1;
}
}
codebook_setup->lookup_type=get_bits(gb, 4);
AV_DEBUG(" lookup type: %d : %s \n", codebook_setup->lookup_type, codebook_setup->lookup_type ? "vq" : "no lookup" );
// If the codebook is used for (inverse) VQ, calculate codevectors.
if (codebook_setup->lookup_type==1) {
uint_fast16_t i, j, k;
uint_fast16_t codebook_lookup_values=nth_root(entries, codebook_setup->dimensions);
uint_fast16_t codebook_multiplicands[codebook_lookup_values];
float codebook_minimum_value=vorbisfloat2float(get_bits_long_le(gb, 32));
float codebook_delta_value=vorbisfloat2float(get_bits_long_le(gb, 32));
uint_fast8_t codebook_value_bits=get_bits(gb, 4)+1;
uint_fast8_t codebook_sequence_p=get_bits1(gb);
AV_DEBUG(" We expect %d numbers for building the codevectors. \n", codebook_lookup_values);
AV_DEBUG(" delta %f minmum %f \n", codebook_delta_value, codebook_minimum_value);
for(i=0;i<codebook_lookup_values;++i) {
codebook_multiplicands[i]=get_bits(gb, codebook_value_bits);
AV_DEBUG(" multiplicands*delta+minmum : %e \n", (float)codebook_multiplicands[i]*codebook_delta_value+codebook_minimum_value);
AV_DEBUG(" multiplicand %d \n", codebook_multiplicands[i]);
}
// Weed out unused vlcs and build codevector vector
codebook_setup->codevectors=(float *)av_mallocz(used_entries*codebook_setup->dimensions * sizeof(float));
for(j=0, i=0;i<entries;++i) {
uint_fast8_t dim=codebook_setup->dimensions;
if (tmp_vlc_bits[i]) {
float last=0.0;
uint_fast32_t lookup_offset=i;
#ifdef V_DEBUG
av_log(vc->avccontext, AV_LOG_INFO, "Lookup offset %d ,", i);
#endif
for(k=0;k<dim;++k) {
uint_fast32_t multiplicand_offset = lookup_offset % codebook_lookup_values;
codebook_setup->codevectors[j*dim+k]=codebook_multiplicands[multiplicand_offset]*codebook_delta_value+codebook_minimum_value+last;
if (codebook_sequence_p) {
last=codebook_setup->codevectors[j*dim+k];
}
lookup_offset/=codebook_lookup_values;
}
tmp_vlc_bits[j]=tmp_vlc_bits[i];
#ifdef V_DEBUG
av_log(vc->avccontext, AV_LOG_INFO, "real lookup offset %d, vector: ", j);
for(k=0;k<dim;++k) {
av_log(vc->avccontext, AV_LOG_INFO, " %f ", codebook_setup->codevectors[j*dim+k]);
}
av_log(vc->avccontext, AV_LOG_INFO, "\n");
#endif
++j;
}
}
if (j!=used_entries) {
av_log(vc->avccontext, AV_LOG_ERROR, "Bug in codevector vector building code. \n");
return 1;
}
entries=used_entries;
}
else if (codebook_setup->lookup_type>=2) {
av_log(vc->avccontext, AV_LOG_ERROR, "Codebook lookup type not supported. \n");
return 1;
}
// Initialize VLC table
if (vorbis_len2vlc(vc, tmp_vlc_bits, tmp_vlc_codes, entries)) {
av_log(vc->avccontext, AV_LOG_ERROR, " Invalid code lengths while generating vlcs. \n");
return 1;
}
codebook_setup->maxdepth=0;
for(t=0;t<entries;++t)
if (tmp_vlc_bits[t]>=codebook_setup->maxdepth) codebook_setup->maxdepth=tmp_vlc_bits[t];
codebook_setup->maxdepth=(codebook_setup->maxdepth+V_NB_BITS-1)/V_NB_BITS;
if (init_vlc(&codebook_setup->vlc, V_NB_BITS, entries, tmp_vlc_bits, sizeof(*tmp_vlc_bits), sizeof(*tmp_vlc_bits), tmp_vlc_codes, sizeof(*tmp_vlc_codes), sizeof(*tmp_vlc_codes), INIT_VLC_LE)) {
av_log(vc->avccontext, AV_LOG_ERROR, " Error generating vlc tables. \n");
return 1;
}
}
return 0;
}
// Process time domain transforms part (unused in Vorbis I)
static int vorbis_parse_setup_hdr_tdtransforms(vorbis_context *vc) {
GetBitContext *gb=&vc->gb;
uint_fast8_t i;
uint_fast8_t vorbis_time_count=get_bits(gb, 6)+1;
for(i=0;i<vorbis_time_count;++i) {
uint_fast16_t vorbis_tdtransform=get_bits(gb, 16);
AV_DEBUG(" Vorbis time domain transform %d: %d \n", vorbis_time_count, vorbis_tdtransform);
if (vorbis_tdtransform) {
av_log(vc->avccontext, AV_LOG_ERROR, "Vorbis time domain transform data nonzero. \n");
return 1;
}
}
return 0;
}
// Process floors part - only floor type 1 is supported
static int vorbis_parse_setup_hdr_floors(vorbis_context *vc) {
GetBitContext *gb=&vc->gb;
uint_fast16_t i,j,k;
vc->floor_count=get_bits(gb, 6)+1;
vc->floors=(vorbis_floor *)av_mallocz(vc->floor_count * sizeof(vorbis_floor));
for (i=0;i<vc->floor_count;++i) {
vorbis_floor *floor_setup=&vc->floors[i];
floor_setup->floor_type=get_bits(gb, 16);
AV_DEBUG(" %d. floor type %d \n", i, floor_setup->floor_type);
if (floor_setup->floor_type==1) {
uint_fast8_t maximum_class=0;
uint_fast8_t rangebits;
uint_fast16_t floor1_values=2;
floor_setup->partitions=get_bits(gb, 5);
AV_DEBUG(" %d.floor: %d partitions \n", i, floor_setup->partitions);
for(j=0;j<floor_setup->partitions;++j) {
floor_setup->partition_class[j]=get_bits(gb, 4);
if (floor_setup->partition_class[j]>maximum_class) maximum_class=floor_setup->partition_class[j];
AV_DEBUG(" %d. floor %d partition class %d \n", i, j, floor_setup->partition_class[j]);
}
AV_DEBUG(" maximum class %d \n", maximum_class);
floor_setup->maximum_class=maximum_class;
for(j=0;j<=maximum_class;++j) {
floor_setup->class_dimensions[j]=get_bits(gb, 3)+1;
floor_setup->class_subclasses[j]=get_bits(gb, 2);
AV_DEBUG(" %d floor %d class dim: %d subclasses %d \n", i, j, floor_setup->class_dimensions[j], floor_setup->class_subclasses[j]);
if (floor_setup->class_subclasses[j]) {
floor_setup->class_masterbook[j]=get_bits(gb, 8);
AV_DEBUG(" masterbook: %d \n", floor_setup->class_masterbook[j]);
}
for(k=0;k<(1<<floor_setup->class_subclasses[j]);++k) {
floor_setup->subclass_books[j][k]=get_bits(gb, 8)-1;
AV_DEBUG(" book %d. : %d \n", k, floor_setup->subclass_books[j][k]);
}
}
floor_setup->multiplier=get_bits(gb, 2)+1;
floor_setup->x_list_dim=2;
for(j=0;j<floor_setup->partitions;++j) {
floor_setup->x_list_dim+=floor_setup->class_dimensions[floor_setup->partition_class[j]];
}
floor_setup->x_list=(uint_fast16_t *)av_mallocz(floor_setup->x_list_dim * sizeof(uint_fast16_t));
floor_setup->x_list_order=(uint_fast16_t *)av_mallocz(floor_setup->x_list_dim * sizeof(uint_fast16_t));
floor_setup->low_neighbour=(uint_fast16_t *)av_mallocz(floor_setup->x_list_dim * sizeof(uint_fast16_t));
floor_setup->high_neighbour=(uint_fast16_t *)av_mallocz(floor_setup->x_list_dim * sizeof(uint_fast16_t));
rangebits=get_bits(gb, 4);
floor_setup->x_list[0] = 0;
floor_setup->x_list[1] = (1<<rangebits);
for(j=0;j<floor_setup->partitions;++j) {
for(k=0;k<floor_setup->class_dimensions[floor_setup->partition_class[j]];++k,++floor1_values) {
floor_setup->x_list[floor1_values]=get_bits(gb, rangebits);
AV_DEBUG(" %d. floor1 Y coord. %d \n", floor1_values, floor_setup->x_list[floor1_values]);
}
}
// Precalculate order of x coordinates - needed for decode
for(k=0;k<floor_setup->x_list_dim;++k) {
floor_setup->x_list_order[k]=k;
}
for(k=0;k<floor_setup->x_list_dim-1;++k) { // FIXME optimize sorting ?
for(j=k+1;j<floor_setup->x_list_dim;++j) {
if(floor_setup->x_list[floor_setup->x_list_order[k]]>floor_setup->x_list[floor_setup->x_list_order[j]]) {
uint_fast16_t tmp=floor_setup->x_list_order[k];
floor_setup->x_list_order[k]=floor_setup->x_list_order[j];
floor_setup->x_list_order[j]=tmp;
}
}
}
// Precalculate low and high neighbours
for(k=2;k<floor_setup->x_list_dim;++k) {
floor_setup->low_neighbour[k]=0;
floor_setup->high_neighbour[k]=1; // correct according to SPEC requirements
for (j=0;j<k;++j) {
if ((floor_setup->x_list[j]<floor_setup->x_list[k]) &&
(floor_setup->x_list[j]>floor_setup->x_list[floor_setup->low_neighbour[k]])) {
floor_setup->low_neighbour[k]=j;
}
if ((floor_setup->x_list[j]>floor_setup->x_list[k]) &&
(floor_setup->x_list[j]<floor_setup->x_list[floor_setup->high_neighbour[k]])) {
floor_setup->high_neighbour[k]=j;
}
}
}
}
else {
av_log(vc->avccontext, AV_LOG_ERROR, "Only floor type 1 supported. \n");
return 1;
}
}
return 0;
}
// Process residues part
static int vorbis_parse_setup_hdr_residues(vorbis_context *vc){
GetBitContext *gb=&vc->gb;
uint_fast8_t i, j, k;
vc->residue_count=get_bits(gb, 6)+1;
vc->residues=(vorbis_residue *)av_mallocz(vc->residue_count * sizeof(vorbis_residue));
AV_DEBUG(" There are %d residues. \n", vc->residue_count);
for(i=0;i<vc->residue_count;++i) {
vorbis_residue *res_setup=&vc->residues[i];
uint_fast8_t cascade[64];
uint_fast8_t high_bits;
uint_fast8_t low_bits;
res_setup->type=get_bits(gb, 16);
AV_DEBUG(" %d. residue type %d \n", i, res_setup->type);
res_setup->begin=get_bits(gb, 24);
res_setup->end=get_bits(gb, 24);
res_setup->partition_size=get_bits(gb, 24)+1;
res_setup->classifications=get_bits(gb, 6)+1;
res_setup->classbook=get_bits(gb, 8);
AV_DEBUG(" begin %d end %d part.size %d classif.s %d classbook %d \n", res_setup->begin, res_setup->end, res_setup->partition_size,
res_setup->classifications, res_setup->classbook);
for(j=0;j<res_setup->classifications;++j) {
high_bits=0;
low_bits=get_bits(gb, 3);
if (get_bits1(gb)) {
high_bits=get_bits(gb, 5);
}
cascade[j]=(high_bits<<3)+low_bits;
AV_DEBUG(" %d class casscade depth: %d \n", j, ilog(cascade[j]));
}
res_setup->maxpass=0;
for(j=0;j<res_setup->classifications;++j) {
for(k=0;k<8;++k) {
if (cascade[j]&(1<<k)) {
res_setup->books[j][k]=get_bits(gb, 8);
AV_DEBUG(" %d class casscade depth %d book: %d \n", j, k, res_setup->books[j][k]);
if (k>res_setup->maxpass) {
res_setup->maxpass=k;
}
} else {
res_setup->books[j][k]=-1;
}
}
}
}
return 0;
}
// Process mappings part
static int vorbis_parse_setup_hdr_mappings(vorbis_context *vc) {
GetBitContext *gb=&vc->gb;
uint_fast8_t i, j;
vc->mapping_count=get_bits(gb, 6)+1;
vc->mappings=(vorbis_mapping *)av_mallocz(vc->mapping_count * sizeof(vorbis_mapping));
AV_DEBUG(" There are %d mappings. \n", vc->mapping_count);
for(i=0;i<vc->mapping_count;++i) {
vorbis_mapping *mapping_setup=&vc->mappings[i];
if (get_bits(gb, 16)) {
av_log(vc->avccontext, AV_LOG_ERROR, "Other mappings than type 0 are not compliant with the Vorbis I specification. \n");
return 1;
}
if (get_bits1(gb)) {
mapping_setup->submaps=get_bits(gb, 4)+1;
} else {
mapping_setup->submaps=1;
}
if (get_bits1(gb)) {
mapping_setup->coupling_steps=get_bits(gb, 8)+1;
mapping_setup->magnitude=(uint_fast8_t *)av_mallocz(mapping_setup->coupling_steps * sizeof(uint_fast8_t));
mapping_setup->angle=(uint_fast8_t *)av_mallocz(mapping_setup->coupling_steps * sizeof(uint_fast8_t));
for(j=0;j<mapping_setup->coupling_steps;++j) {
mapping_setup->magnitude[j]=get_bits(gb, ilog(vc->audio_channels-1));
mapping_setup->angle[j]=get_bits(gb, ilog(vc->audio_channels-1));
// FIXME: sanity checks
}
} else {
mapping_setup->coupling_steps=0;
}
AV_DEBUG(" %d mapping coupling steps: %d \n", i, mapping_setup->coupling_steps);
if(get_bits(gb, 2)) {
av_log(vc->avccontext, AV_LOG_ERROR, "%d. mapping setup data invalid. \n", i);
return 1; // following spec.
}
if (mapping_setup->submaps>1) {
mapping_setup->mux=(uint_fast8_t *)av_mallocz(vc->audio_channels * sizeof(uint_fast8_t));
for(j=0;j<vc->audio_channels;++j) {
mapping_setup->mux[j]=get_bits(gb, 4);
}
}
for(j=0;j<mapping_setup->submaps;++j) {
get_bits(gb, 8); // FIXME check?
mapping_setup->submap_floor[j]=get_bits(gb, 8);
mapping_setup->submap_residue[j]=get_bits(gb, 8);
AV_DEBUG(" %d mapping %d submap : floor %d, residue %d \n", i, j, mapping_setup->submap_floor[j], mapping_setup->submap_residue[j]);
}
}
return 0;
}
// Process modes part
static int vorbis_parse_setup_hdr_modes(vorbis_context *vc) {
GetBitContext *gb=&vc->gb;
uint_fast8_t i;
vc->mode_count=get_bits(gb, 6)+1;
vc->modes=(vorbis_mode *)av_mallocz(vc->mode_count * sizeof(vorbis_mode));
AV_DEBUG(" There are %d modes.\n", vc->mode_count);
for(i=0;i<vc->mode_count;++i) {
vorbis_mode *mode_setup=&vc->modes[i];
mode_setup->blockflag=get_bits(gb, 1);
mode_setup->windowtype=get_bits(gb, 16); //FIXME check
mode_setup->transformtype=get_bits(gb, 16); //FIXME check
mode_setup->mapping=get_bits(gb, 8); //FIXME check
AV_DEBUG(" %d mode: blockflag %d, windowtype %d, transformtype %d, mapping %d \n", i, mode_setup->blockflag, mode_setup->windowtype, mode_setup->transformtype, mode_setup->mapping);
}
return 0;
}
// Process the whole setup header using the functions above
static int vorbis_parse_setup_hdr(vorbis_context *vc) {
GetBitContext *gb=&vc->gb;
if ((get_bits(gb, 8)!='v') || (get_bits(gb, 8)!='o') ||
(get_bits(gb, 8)!='r') || (get_bits(gb, 8)!='b') ||
(get_bits(gb, 8)!='i') || (get_bits(gb, 8)!='s')) {
av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (no vorbis signature). \n");
return 1;
}
if (vorbis_parse_setup_hdr_codebooks(vc)) {
av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (codebooks). \n");
return 2;
}
if (vorbis_parse_setup_hdr_tdtransforms(vc)) {
av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (time domain transforms). \n");
return 3;
}
if (vorbis_parse_setup_hdr_floors(vc)) {
av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (floors). \n");
return 4;
}
if (vorbis_parse_setup_hdr_residues(vc)) {
av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (residues). \n");
return 5;
}
if (vorbis_parse_setup_hdr_mappings(vc)) {
av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (mappings). \n");
return 6;
}
if (vorbis_parse_setup_hdr_modes(vc)) {
av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (modes). \n");
return 7;
}
if (!get_bits1(gb)) {
av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (framing flag). \n");
return 8; // framing flag bit unset error
}
return 0;
}
// Process the identification header
static int vorbis_parse_id_hdr(vorbis_context *vc){
GetBitContext *gb=&vc->gb;
uint_fast8_t bl0, bl1;
const float *vwin[8]={ vwin64, vwin128, vwin256, vwin512, vwin1024, vwin2048, vwin4096, vwin8192 };
if ((get_bits(gb, 8)!='v') || (get_bits(gb, 8)!='o') ||
(get_bits(gb, 8)!='r') || (get_bits(gb, 8)!='b') ||
(get_bits(gb, 8)!='i') || (get_bits(gb, 8)!='s')) {
av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis id header packet corrupt (no vorbis signature). \n");
return 1;
}
vc->version=get_bits_long_le(gb, 32); //FIXME check 0
vc->audio_channels=get_bits(gb, 8); //FIXME check >0
vc->audio_samplerate=get_bits_long_le(gb, 32); //FIXME check >0
vc->bitrate_maximum=get_bits_long_le(gb, 32);
vc->bitrate_nominal=get_bits_long_le(gb, 32);
vc->bitrate_minimum=get_bits_long_le(gb, 32);
bl0=get_bits(gb, 4);
bl1=get_bits(gb, 4);
vc->blocksize_0=(1<<bl0);
vc->blocksize_1=(1<<bl1);
if (bl0>13 || bl0<6 || bl1>13 || bl1<6) {
av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis id header packet corrupt (illegal blocksize). \n");
return 3;
}
vc->swin=vwin[bl0-6];
vc->lwin=vwin[bl1-6];
if ((get_bits1(gb)) == 0) {
av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis id header packet corrupt (framing flag not set). \n");
return 2;
}
vc->channel_residues=(float *)av_malloc((vc->blocksize_1/2)*vc->audio_channels * sizeof(float));
vc->channel_floors=(float *)av_malloc((vc->blocksize_1/2)*vc->audio_channels * sizeof(float));
vc->saved=(float *)av_malloc((vc->blocksize_1/2)*vc->audio_channels * sizeof(float));
vc->ret=(float *)av_malloc((vc->blocksize_1/2)*vc->audio_channels * sizeof(float));
vc->saved_start=0;
ff_mdct_init(&vc->mdct0, bl0, 1);
ff_mdct_init(&vc->mdct1, bl1, 1);
AV_DEBUG(" vorbis version %d \n audio_channels %d \n audio_samplerate %d \n bitrate_max %d \n bitrate_nom %d \n bitrate_min %d \n blk_0 %d blk_1 %d \n ",
vc->version, vc->audio_channels, vc->audio_samplerate, vc->bitrate_maximum, vc->bitrate_nominal, vc->bitrate_minimum, vc->blocksize_0, vc->blocksize_1);
/*
BLK=vc->blocksize_0;
for(i=0;i<BLK/2;++i) {
vc->swin[i]=sin(0.5*3.14159265358*(sin(((float)i+0.5)/(float)BLK*3.14159265358))*(sin(((float)i+0.5)/(float)BLK*3.14159265358)));
}
*/
return 0;
}
// Process the extradata using the functions above (identification header, setup header)
static int vorbis_decode_init(AVCodecContext *avccontext) {
vorbis_context *vc = avccontext->priv_data ;
uint8_t *headers = avccontext->extradata;
int headers_len=avccontext->extradata_size;
int header_len[3];
GetBitContext *gb = &(vc->gb);
int i, j, hdr_type;
vc->avccontext = avccontext;
if (!headers_len || headers[0]!=2) {
av_log(avccontext, AV_LOG_ERROR, "Extradata corrupt.\n");
return -1;
}
for(j=1,i=0;i<2;++i, ++j) {
header_len[i]=0;
while(j<headers_len && headers[j]==0xff) {
header_len[i]+=0xff;
++j;
}
if (j>=headers_len) {
av_log(avccontext, AV_LOG_ERROR, "Extradata corrupt.\n");
return -1;
}
header_len[i]+=headers[j];
}
header_len[2]=headers_len-header_len[0]-header_len[1]-j;
headers+=j;
init_get_bits(gb, headers, header_len[0]*8);
hdr_type=get_bits(gb, 8);
if (hdr_type!=1) {
av_log(avccontext, AV_LOG_ERROR, "First header is not the id header.\n");
return -1;
}
if (vorbis_parse_id_hdr(vc)) {
av_log(avccontext, AV_LOG_ERROR, "Id header corrupt.\n");
vorbis_free(vc);
return -1;
}
init_get_bits(gb, headers+header_len[0]+header_len[1], header_len[2]*8);
hdr_type=get_bits(gb, 8);
if (hdr_type!=5) {
av_log(avccontext, AV_LOG_ERROR, "Third header is not the setup header.\n");
return -1;
}
if (vorbis_parse_setup_hdr(vc)) {
av_log(avccontext, AV_LOG_ERROR, "Setup header corrupt.\n");
vorbis_free(vc);
return -1;
}
avccontext->channels = vc->audio_channels;
avccontext->sample_rate = vc->audio_samplerate;
return 0 ;
}
// Decode audiopackets -------------------------------------------------
// Read and decode floor (type 1 only)
static uint_fast8_t vorbis_floor1_decode(vorbis_context *vc, vorbis_floor *vf, float *vec) {
GetBitContext *gb=&vc->gb;
uint_fast16_t range_v[4]={ 256, 128, 86, 64 };
uint_fast16_t range=range_v[vf->multiplier-1];
uint_fast16_t floor1_Y[vf->x_list_dim];
uint_fast16_t floor1_Y_final[vf->x_list_dim];
uint_fast8_t floor1_flag[vf->x_list_dim];
uint_fast8_t class_;
uint_fast8_t cdim;
uint_fast8_t cbits;
uint_fast8_t csub;
uint_fast8_t cval;
int_fast16_t book;
uint_fast16_t offset;
uint_fast16_t i,j;
uint_fast16_t *floor_x_sort=vf->x_list_order;
/*u*/int_fast16_t adx, ady, off, predicted; // WTF ? dy/adx= (unsigned)dy/adx ?
int_fast16_t dy, err;
uint_fast16_t lx,hx, ly, hy=0;
if (!get_bits1(gb)) return 1; // silence
// Read values (or differences) for the floor's points
floor1_Y[0]=get_bits(gb, ilog(range-1));
floor1_Y[1]=get_bits(gb, ilog(range-1));
AV_DEBUG("floor 0 Y %d floor 1 Y %d \n", floor1_Y[0], floor1_Y[1]);
offset=2;
for(i=0;i<vf->partitions;++i) {
class_=vf->partition_class[i];
cdim=vf->class_dimensions[class_];
cbits=vf->class_subclasses[class_];
csub=(1<<cbits)-1;
cval=0;
AV_DEBUG("Cbits %d \n", cbits);
if (cbits) { // this reads all subclasses for this partition's class
cval=get_vlc2(gb, vc->codebooks[vf->class_masterbook[class_]].vlc.table,
V_NB_BITS, vc->codebooks[vf->class_masterbook[class_]].maxdepth);
}
for(j=0;j<cdim;++j) {
book=vf->subclass_books[class_][cval & csub];
AV_DEBUG("book %d Cbits %d cval %d bits:%d \n", book, cbits, cval, get_bits_count(gb));
cval=cval>>cbits;
if (book>0) {
floor1_Y[offset+j]=get_vlc2(gb, vc->codebooks[book].vlc.table,
V_NB_BITS, vc->codebooks[book].maxdepth);
} else {
floor1_Y[offset+j]=0;
}
AV_DEBUG(" floor(%d) = %d \n", vf->x_list[offset+j], floor1_Y[offset+j]);
}
offset+=cdim;
}
// Amplitude calculation from the differences
floor1_flag[0]=1;
floor1_flag[1]=1;
floor1_Y_final[0]=floor1_Y[0];
floor1_Y_final[1]=floor1_Y[1];
for(i=2;i<vf->x_list_dim;++i) {
uint_fast16_t val, highroom, lowroom, room;
uint_fast16_t high_neigh_offs;
uint_fast16_t low_neigh_offs;
low_neigh_offs=vf->low_neighbour[i];
high_neigh_offs=vf->high_neighbour[i];
dy=floor1_Y_final[high_neigh_offs]-floor1_Y_final[low_neigh_offs]; // render_point begin
adx=vf->x_list[high_neigh_offs]-vf->x_list[low_neigh_offs];
ady= ABS(dy);
err=ady*(vf->x_list[i]-vf->x_list[low_neigh_offs]);
off=err/adx;
if (dy<0) {
predicted=floor1_Y_final[low_neigh_offs]-off;
} else {
predicted=floor1_Y_final[low_neigh_offs]+off;
} // render_point end
val=floor1_Y[i];
highroom=range-predicted;
lowroom=predicted;
if (highroom < lowroom) {
room=highroom*2;
} else {
room=lowroom*2; // SPEC mispelling
}
if (val) {
floor1_flag[low_neigh_offs]=1;
floor1_flag[high_neigh_offs]=1;
floor1_flag[i]=1;
if (val>=room) {
if (highroom > lowroom) {
floor1_Y_final[i]=val-lowroom+predicted;
} else {
floor1_Y_final[i]=predicted-val+highroom-1;
}
} else {
if (val & 1) {
floor1_Y_final[i]=predicted-(val+1)/2;
} else {
floor1_Y_final[i]=predicted+val/2;
}
}
} else {
floor1_flag[i]=0;
floor1_Y_final[i]=predicted;
}
AV_DEBUG(" Decoded floor(%d) = %d / val %d \n", vf->x_list[i], floor1_Y_final[i], val);
}
// Curve synth - connect the calculated dots and convert from dB scale FIXME optimize ?
hx=0;
lx=0;
ly=floor1_Y_final[0]*vf->multiplier; // conforms to SPEC
vec[0]=floor1_inverse_db_table[ly];
for(i=1;i<vf->x_list_dim;++i) {
AV_DEBUG(" Looking at post %d \n", i);
if (floor1_flag[floor_x_sort[i]]) { // SPEC mispelled
int_fast16_t x, y, dy, base, sy; // if uncommented: dy = -32 adx = 2 base = 2blablabla ?????
hy=floor1_Y_final[floor_x_sort[i]]*vf->multiplier;
hx=vf->x_list[floor_x_sort[i]];
dy=hy-ly;
adx=hx-lx;
ady= (dy<0) ? -dy:dy;//ABS(dy);
base=dy/adx;
AV_DEBUG(" dy %d adx %d base %d = %d \n", dy, adx, base, dy/adx);
x=lx;
y=ly;
err=0;
if (dy<0) {
sy=base-1;
} else {
sy=base+1;
}
ady=ady-(base<0 ? -base : base)*adx;
vec[x]=floor1_inverse_db_table[y];
AV_DEBUG(" vec[ %d ] = %d \n", x, y);
for(x=lx+1;(x<hx) && (x<vf->x_list[1]);++x) {
err+=ady;
if (err>=adx) {
err-=adx;
y+=sy;
} else {
y+=base;
}
vec[x]=floor1_inverse_db_table[y];
AV_DEBUG(" vec[ %d ] = %d \n", x, y);
}
/* for(j=1;j<hx-lx+1;++j) { // iterating render_point
dy=hy-ly;
adx=hx-lx;
ady= dy<0 ? -dy : dy;
err=ady*j;
off=err/adx;
if (dy<0) {
predicted=ly-off;
} else {
predicted=ly+off;
}
if (lx+j < vf->x_list[1]) {
vec[lx+j]=floor1_inverse_db_table[predicted];
}
}*/
lx=hx;
ly=hy;
}
}
if (hx<vf->x_list[1]) {
for(i=hx;i<vf->x_list[1];++i) {
vec[i]=floor1_inverse_db_table[hy];
}
}
AV_DEBUG(" Floor decoded\n");
return 0;
}
// Read and decode residue
static int vorbis_residue_decode(vorbis_context *vc, vorbis_residue *vr, uint_fast8_t ch, uint_fast8_t *do_not_decode, float *vec, uint_fast16_t vlen) {
GetBitContext *gb=&vc->gb;
uint_fast8_t c_p_c=vc->codebooks[vr->classbook].dimensions;
uint_fast16_t n_to_read=vr->end-vr->begin;
uint_fast16_t ptns_to_read=n_to_read/vr->partition_size;
uint_fast8_t classifs[ptns_to_read];
uint_fast8_t pass;
uint_fast8_t ch_used;
uint_fast8_t i,j,l;
uint_fast16_t k;
if (vr->type==2) {
for(j=1;j<ch;++j) {
do_not_decode[0]&=do_not_decode[j]; // FIXME - clobbering input
}
if (do_not_decode[0]) return 0;
ch_used=1;
} else {
ch_used=ch;
}
AV_DEBUG(" residue type 0/1/2 decode begin, ch: %d cpc %d \n", ch, c_p_c);
for(pass=0;pass<=vr->maxpass;++pass) { // FIXME OPTIMIZE?
uint_fast16_t voffset;
uint_fast16_t partition_count;
uint_fast16_t j_times_ptns_to_read;
voffset=vr->begin;
for(partition_count=0;partition_count<ptns_to_read;) { // SPEC error
if (!pass) {
for(j_times_ptns_to_read=0, j=0;j<ch_used;++j) {
if (!do_not_decode[j]) {
uint_fast32_t temp=get_vlc2(gb, vc->codebooks[vr->classbook].vlc.table,
V_NB_BITS, vc->codebooks[vr->classbook].maxdepth);
AV_DEBUG("Classword: %d \n", temp);
for(i=0;i<c_p_c;++i) {
uint_fast32_t temp2;
temp2=temp/vr->classifications;
classifs[j_times_ptns_to_read+partition_count+c_p_c-1-i]=temp-temp2*vr->classifications;
temp=temp2;
}
}
j_times_ptns_to_read+=ptns_to_read;
}
}
for(i=0;(i<c_p_c) && (partition_count<ptns_to_read);++i) {
for(j_times_ptns_to_read=0, j=0;j<ch_used;++j) {
uint_fast16_t voffs;
if (!do_not_decode[j]) {
uint_fast8_t vqclass=classifs[j_times_ptns_to_read+partition_count];
int_fast16_t vqbook=vr->books[vqclass][pass];
if (vqbook>=0) {
uint_fast16_t coffs;
if (vr->type==0) {
uint_fast16_t step=vr->partition_size/vc->codebooks[vqbook].dimensions;
voffs=voffset+j*vlen;
for(k=0;k<step;++k) {
coffs=get_vlc2(gb, vc->codebooks[vqbook].vlc.table,
V_NB_BITS, vc->codebooks[vr->classbook].maxdepth) * vc->codebooks[vqbook].dimensions;
for(l=0;l<vc->codebooks[vqbook].dimensions;++l) {
vec[voffs+k+l*step]+=vc->codebooks[vqbook].codevectors[coffs+l]; // FPMATH
}
}
}
else if (vr->type==1) {
voffs=voffset+j*vlen;
for(k=0;k<vr->partition_size/vc->codebooks[vqbook].dimensions;++k) {
coffs=get_vlc2(gb, vc->codebooks[vqbook].vlc.table,
V_NB_BITS, vc->codebooks[vr->classbook].maxdepth) * vc->codebooks[vqbook].dimensions;
for(l=0;l<vc->codebooks[vqbook].dimensions;++l, ++voffs) {
vec[voffs]+=vc->codebooks[vqbook].codevectors[coffs+l]; // FPMATH
AV_DEBUG(" pass %d offs: %d curr: %f change: %f cv offs.: %d \n", pass, voffs, vec[voffs], vc->codebooks[vqbook].codevectors[coffs+l], coffs);
}
}
}
else if (vr->type==2 && ch==2) { // most frequent case optimized
voffs=voffset;
for(k=0;k<vr->partition_size/vc->codebooks[vqbook].dimensions;++k) {
coffs=get_vlc2(gb, vc->codebooks[vqbook].vlc.table,
V_NB_BITS, vc->codebooks[vr->classbook].maxdepth) * vc->codebooks[vqbook].dimensions;
for(l=0;l<vc->codebooks[vqbook].dimensions;++l, ++voffs) {
vec[(voffs>>1)+((voffs&1) ? vlen : 0)]+=vc->codebooks[vqbook].codevectors[coffs+l]; // FPMATH
AV_DEBUG(" pass %d offs: %d curr: %f change: %f cv offs.: %d+%d \n", pass, voffset/ch+(voffs%ch)*vlen, vec[voffset/ch+(voffs%ch)*vlen], vc->codebooks[vqbook].codevectors[coffs+l], coffs, l);
}
}
}
else if (vr->type==2) {
voffs=voffset;
for(k=0;k<vr->partition_size/vc->codebooks[vqbook].dimensions;++k) {
coffs=get_vlc2(gb, vc->codebooks[vqbook].vlc.table,
V_NB_BITS, vc->codebooks[vr->classbook].maxdepth) * vc->codebooks[vqbook].dimensions;
for(l=0;l<vc->codebooks[vqbook].dimensions;++l, ++voffs) {
vec[voffs/ch+(voffs%ch)*vlen]+=vc->codebooks[vqbook].codevectors[coffs+l]; // FPMATH FIXME use if and counter instead of / and %
AV_DEBUG(" pass %d offs: %d curr: %f change: %f cv offs.: %d+%d \n", pass, voffset/ch+(voffs%ch)*vlen, vec[voffset/ch+(voffs%ch)*vlen], vc->codebooks[vqbook].codevectors[coffs+l], coffs, l);
}
}
} else {
av_log(vc->avccontext, AV_LOG_ERROR, " Invalid residue type while residue decode?! \n");
return 1;
}
}
j_times_ptns_to_read+=ptns_to_read;
}
}
++partition_count;
voffset+=vr->partition_size;
}
}
}
return 0;
}
// Decode the audio packet using the functions above
static int vorbis_parse_audio_packet(vorbis_context *vc) {
GetBitContext *gb=&vc->gb;
uint_fast8_t previous_window=0,next_window=0;
uint_fast8_t mode_number;
uint_fast16_t blocksize;
int_fast32_t i,j;
uint_fast8_t no_residue[vc->audio_channels];
uint_fast8_t do_not_decode[vc->audio_channels];
vorbis_mapping *mapping;
float *ch_res_ptr=vc->channel_residues;
float *ch_floor_ptr=vc->channel_floors;
uint_fast8_t res_chan[vc->audio_channels];
uint_fast8_t res_num=0;
int_fast16_t retlen=0;
uint_fast16_t saved_start=0;
if (get_bits1(gb)) {
av_log(vc->avccontext, AV_LOG_ERROR, "Not a Vorbis I audio packet.\n");
return -1; // packet type not audio
}
mode_number=get_bits(gb, ilog(vc->mode_count-1));
mapping=&vc->mappings[vc->modes[mode_number].mapping];
AV_DEBUG(" Mode number: %d , mapping: %d , blocktype %d \n", mode_number, vc->modes[mode_number].mapping, vc->modes[mode_number].blockflag);
if (vc->modes[mode_number].blockflag) {
previous_window=get_bits1(gb);
next_window=get_bits1(gb);
}
blocksize=vc->modes[mode_number].blockflag ? vc->blocksize_1 : vc->blocksize_0;
memset(ch_res_ptr, 0, sizeof(float)*vc->audio_channels*blocksize/2); //FIXME can this be removed ?
memset(ch_floor_ptr, 0, sizeof(float)*vc->audio_channels*blocksize/2); //FIXME can this be removed ?
// Decode floor(1)
for(i=0;i<vc->audio_channels;++i) {
vorbis_floor *floor;
if (mapping->submaps>1) {
floor=&vc->floors[mapping->submap_floor[mapping->mux[i]]];
} else {
floor=&vc->floors[mapping->submap_floor[0]];
}
no_residue[i]=vorbis_floor1_decode(vc, floor, ch_floor_ptr);
ch_floor_ptr+=blocksize/2;
}
// Nonzero vector propagate
for(i=mapping->coupling_steps-1;i>=0;--i) {
if (!(no_residue[mapping->magnitude[i]] & no_residue[mapping->angle[i]])) {
no_residue[mapping->magnitude[i]]=0;
no_residue[mapping->angle[i]]=0;
}
}
// Decode residue
for(i=0;i<mapping->submaps;++i) {
vorbis_residue *residue;
uint_fast8_t ch=0;
for(j=0;j<vc->audio_channels;++j) {
if ((mapping->submaps==1) || (i=mapping->mux[j])) {
res_chan[j]=res_num;
if (no_residue[j]) {
do_not_decode[ch]=1;
} else {
do_not_decode[ch]=0;
}
++ch;
++res_num;
}
}
residue=&vc->residues[mapping->submap_residue[i]];
vorbis_residue_decode(vc, residue, ch, do_not_decode, ch_res_ptr, blocksize/2);
ch_res_ptr+=ch*blocksize/2;
}
// Inverse coupling
for(i=mapping->coupling_steps-1;i>=0;--i) { //warning: i has to be signed
float *mag, *ang;
mag=vc->channel_residues+res_chan[mapping->magnitude[i]]*blocksize/2;
ang=vc->channel_residues+res_chan[mapping->angle[i]]*blocksize/2;
for(j=0;j<blocksize/2;++j) {
float temp;
if (mag[j]>0.0) {
if (ang[j]>0.0) {
ang[j]=mag[j]-ang[j];
} else {
temp=ang[j];
ang[j]=mag[j];
mag[j]+=temp;
}
} else {
if (ang[j]>0.0) {
ang[j]+=mag[j];
} else {
temp=ang[j];
ang[j]=mag[j];
mag[j]-=temp;
}
}
}
}
// Dotproduct
for(j=0, ch_floor_ptr=vc->channel_floors;j<vc->audio_channels;++j,ch_floor_ptr+=blocksize/2) {
ch_res_ptr=vc->channel_residues+res_chan[j]*blocksize/2;
for(i=0;i<blocksize/2;++i) {
ch_floor_ptr[i]*=ch_res_ptr[i]; //FPMATH
}
}
// MDCT, overlap/add, save data for next overlapping FPMATH
for(j=0;j<vc->audio_channels;++j) {
uint_fast8_t step=vc->audio_channels;
uint_fast16_t k;
float *saved=vc->saved+j*vc->blocksize_1/2;
float *ret=vc->ret;
const float *lwin=vc->lwin;
const float *swin=vc->swin;
float buf[blocksize];
float buf_tmp[blocksize];
ch_floor_ptr=vc->channel_floors+j*blocksize/2;
saved_start=vc->saved_start;
ff_imdct_calc(vc->modes[mode_number].blockflag ? &vc->mdct1 : &vc->mdct0, buf, ch_floor_ptr, buf_tmp);
if (vc->modes[mode_number].blockflag) {
// -- overlap/add
if (previous_window) {
for(k=j, i=0;i<vc->blocksize_1/2;++i, k+=step) {
ret[k]=saved[i]+buf[i]*lwin[i];
}
retlen=vc->blocksize_1/2;
} else {
for(k=j, i=0;i<vc->blocksize_0/2;++i, k+=step) {
ret[k]=saved[i]+buf[(vc->blocksize_1-vc->blocksize_0)/4+i]*swin[i];
}
for(i=0;i<(vc->blocksize_1-vc->blocksize_0)/4;++i, k+=step) {
ret[k]=buf[vc->blocksize_0/2+(vc->blocksize_1-vc->blocksize_0)/4+i];
}
retlen=vc->blocksize_0/2+(vc->blocksize_1-vc->blocksize_0)/4;
}
// -- save
if (next_window) {
for(i=0;i<vc->blocksize_1/2;++i) {
saved[i]=buf[vc->blocksize_1/2+i]*lwin[vc->blocksize_1/2-1-i];
}
saved_start=0;
} else {
saved_start=(vc->blocksize_1-vc->blocksize_0)/4;
for(i=0;i<saved_start;++i) {
saved[i]=buf[vc->blocksize_1/2+i];
}
for(i=0;i<vc->blocksize_0/2;++i) {
saved[saved_start+i]=buf[vc->blocksize_1/2+saved_start+i]*swin[vc->blocksize_0/2-1-i];
}
}
} else {
// --overlap/add
for(k=j, i=0;i<saved_start;++i, k+=step) {
ret[k]=saved[i];
}
for(i=0;i<vc->blocksize_0/2;++i, k+=step) {
ret[k]=saved[saved_start+i]+buf[i]*swin[i];
}
retlen=saved_start+vc->blocksize_0/2;
// -- save
for(i=0;i<vc->blocksize_0/2;++i) {
saved[i]=buf[vc->blocksize_0/2+i]*swin[vc->blocksize_0/2-1-i];
}
saved_start=0;
}
}
vc->saved_start=saved_start;
return retlen*vc->audio_channels;
}
// Return the decoded audio packet through the standard api
static int vorbis_decode_frame(AVCodecContext *avccontext,
void *data, int *data_size,
uint8_t *buf, int buf_size)
{
vorbis_context *vc = avccontext->priv_data ;
GetBitContext *gb = &(vc->gb);
int_fast16_t i, len;
if(!buf_size){
return 0;
}
AV_DEBUG("packet length %d \n", buf_size);
init_get_bits(gb, buf, buf_size*8);
len=vorbis_parse_audio_packet(vc);
if (len<=0) {
*data_size=0;
return buf_size;
}
if (!vc->first_frame) {
vc->first_frame=1;
*data_size=0;
return buf_size ;
}
AV_DEBUG("parsed %d bytes %d bits, returned %d samples (*ch*bits) \n", get_bits_count(gb)/8, get_bits_count(gb)%8, len);
for(i=0;i<len;++i) {
int_fast32_t tmp;
tmp=vc->ret[i]*32768;
if (tmp>32767) tmp=32767;
if (tmp<-32768) tmp=-32768;
((int16_t*)data)[i]=tmp;
}
*data_size=len*2;
return buf_size ;
}
// Close decoder
static int vorbis_decode_close(AVCodecContext *avccontext) {
vorbis_context *vc = avccontext->priv_data;
vorbis_free(vc);
return 0 ;
}
AVCodec vorbis_decoder = {
"vorbis",
CODEC_TYPE_AUDIO,
CODEC_ID_VORBIS,
sizeof(vorbis_context),
vorbis_decode_init,
NULL,
vorbis_decode_close,
vorbis_decode_frame,
};