[FFmpeg-devel] [PATCH 5/6] vorbisdec: remove variable-length arrays

Mans Rullgard mans
Wed Aug 19 03:23:01 CEST 2009


---
 libavcodec/vorbis_dec.c |   42 +++++++++++++++++++++++++++++++-----------
 1 files changed, 31 insertions(+), 11 deletions(-)

diff --git a/libavcodec/vorbis_dec.c b/libavcodec/vorbis_dec.c
index bb582c2..4edb234 100644
--- a/libavcodec/vorbis_dec.c
+++ b/libavcodec/vorbis_dec.c
@@ -104,6 +104,8 @@ typedef struct {
     uint_fast8_t classbook;
     int_fast16_t books[64][8];
     uint_fast8_t maxpass;
+    uint_fast16_t ptns_to_read;
+    uint_fast8_t *classifs;
 } vorbis_residue;
 
 typedef struct {
@@ -155,6 +157,9 @@ typedef struct vorbis_context_s {
     float *saved;
     uint_fast32_t add_bias; // for float->int conversion
     uint_fast32_t exp_bias;
+    uint_fast8_t *no_residue;
+    uint_fast8_t *do_not_decode;
+    uint_fast8_t *res_chan;
 } vorbis_context;
 
 /* Helper functions */
@@ -178,7 +183,12 @@ static void vorbis_free(vorbis_context *vc) {
     av_freep(&vc->channel_residues);
     av_freep(&vc->channel_floors);
     av_freep(&vc->saved);
+    av_freep(&vc->no_residue);
+    av_freep(&vc->do_not_decode);
+    av_freep(&vc->res_chan);
 
+    for (i = 0; i < vc->residue_count; i++)
+        av_free(vc->residues[i].classifs);
     av_freep(&vc->residues);
     av_freep(&vc->modes);
 
@@ -220,6 +230,7 @@ static int vorbis_parse_setup_hdr_codebooks(vorbis_context *vc) {
     uint_fast16_t cb;
     uint8_t *tmp_vlc_bits;
     uint32_t *tmp_vlc_codes;
+    uint_fast16_t *codebook_multiplicands;
     GetBitContext *gb=&vc->gb;
 
     vc->codebook_count=get_bits(gb,8)+1;
@@ -229,6 +240,7 @@ static int vorbis_parse_setup_hdr_codebooks(vorbis_context *vc) {
     vc->codebooks=av_mallocz(vc->codebook_count * sizeof(vorbis_codebook));
     tmp_vlc_bits =av_mallocz(V_MAX_VLCS * sizeof(uint8_t));
     tmp_vlc_codes=av_mallocz(V_MAX_VLCS * sizeof(uint32_t));
+    codebook_multiplicands = av_malloc(V_MAX_VLCS * sizeof(*codebook_multiplicands));
 
     for(cb=0;cb<vc->codebook_count;++cb) {
         vorbis_codebook *codebook_setup=&vc->codebooks[cb];
@@ -322,7 +334,6 @@ static int vorbis_parse_setup_hdr_codebooks(vorbis_context *vc) {
         if (codebook_setup->lookup_type==1) {
             uint_fast16_t i, j, k;
             uint_fast16_t codebook_lookup_values=ff_vorbis_nth_root(entries, codebook_setup->dimensions);
-            uint_fast16_t codebook_multiplicands[codebook_lookup_values];
 
             float codebook_minimum_value=vorbisfloat2float(get_bits_long(gb, 32));
             float codebook_delta_value=vorbisfloat2float(get_bits_long(gb, 32));
@@ -406,12 +417,14 @@ static int vorbis_parse_setup_hdr_codebooks(vorbis_context *vc) {
 
     av_free(tmp_vlc_bits);
     av_free(tmp_vlc_codes);
+    av_free(codebook_multiplicands);
     return 0;
 
 // Error:
 error:
     av_free(tmp_vlc_bits);
     av_free(tmp_vlc_codes);
+    av_free(codebook_multiplicands);
     return 1;
 }
 
@@ -631,6 +644,11 @@ static int vorbis_parse_setup_hdr_residues(vorbis_context *vc){
         res_setup->partition_size=get_bits(gb, 24)+1;
         res_setup->classifications=get_bits(gb, 6)+1;
         res_setup->classbook=get_bits(gb, 8);
+        res_setup->ptns_to_read =
+            (res_setup->end - res_setup->begin) / res_setup->partition_size;
+        res_setup->classifs = av_malloc(res_setup->ptns_to_read *
+                                        vc->audio_channels *
+                                        sizeof(*res_setup->classifs));
 
         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);
@@ -879,6 +897,9 @@ static int vorbis_parse_id_hdr(vorbis_context *vc){
     vc->channel_residues= av_malloc((vc->blocksize[1]/2)*vc->audio_channels * sizeof(float));
     vc->channel_floors  = av_malloc((vc->blocksize[1]/2)*vc->audio_channels * sizeof(float));
     vc->saved           = av_mallocz((vc->blocksize[1]/4)*vc->audio_channels * sizeof(float));
+    vc->no_residue      = av_malloc(vc->audio_channels*sizeof(*vc->no_residue));
+    vc->do_not_decode   = av_malloc(vc->audio_channels*sizeof(*vc->do_not_decode));
+    vc->res_chan        = av_malloc(vc->audio_channels*sizeof(*vc->res_chan));
     vc->previous_window=0;
 
     ff_mdct_init(&vc->mdct[0], bl0, 1, vc->exp_bias ? -(1<<15) : -1.0);
@@ -1084,9 +1105,9 @@ static uint_fast8_t vorbis_floor1_decode(vorbis_context *vc, vorbis_floor_data *
     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];
-    int floor1_flag[vf->x_list_dim];
+    uint_fast16_t floor1_Y[258];
+    uint_fast16_t floor1_Y_final[258];
+    int floor1_flag[258];
     uint_fast8_t class_;
     uint_fast8_t cdim;
     uint_fast8_t cbits;
@@ -1213,9 +1234,8 @@ static uint_fast8_t vorbis_floor1_decode(vorbis_context *vc, vorbis_floor_data *
 static av_always_inline int vorbis_residue_decode_internal(vorbis_context *vc, vorbis_residue *vr, uint_fast8_t ch, uint_fast8_t *do_not_decode, float *vec, uint_fast16_t vlen, int vr_type) {
     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*vc->audio_channels];
+    uint_fast16_t ptns_to_read = vr->ptns_to_read;
+    uint_fast8_t *classifs = vr->classifs;
     uint_fast8_t pass;
     uint_fast8_t ch_used;
     uint_fast8_t i,j,l;
@@ -1412,12 +1432,12 @@ static int vorbis_parse_audio_packet(vorbis_context *vc) {
     uint_fast8_t blockflag;
     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];
+    uint_fast8_t *no_residue = vc->no_residue;
+    uint_fast8_t *do_not_decode = vc->do_not_decode;
     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_chan = vc->res_chan;
     uint_fast8_t res_num=0;
     int_fast16_t retlen=0;
     float fadd_bias = vc->add_bias;
@@ -1550,7 +1570,7 @@ static int vorbis_decode_frame(AVCodecContext *avccontext,
     int buf_size = avpkt->size;
     vorbis_context *vc = avccontext->priv_data ;
     GetBitContext *gb = &(vc->gb);
-    const float *channel_ptrs[vc->audio_channels];
+    const float *channel_ptrs[255];
     int i;
 
     int_fast16_t len;
-- 
1.6.4




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