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Code Issues Releases Activity

Use a list to track which fragments coded in this frame still have

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outstanding coefficients yet to be decoded from the bitstream. Once a
fragment reaches end-of-block, remove it from this new list. This change
makes the VP3/Theora entropy decode process dramatically faster due to
not having to iterate incessantly over fragments which have already been
fully decoded.

Originally committed as revision 20698 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Mike Melanson 2009-12-02 02:30:15 +00:00
parent 5dad039bf7
commit 098523eb28
1 changed files with 70 additions and 21 deletions
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91
libavcodec/vp3.c
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@ -179,6 +179,14 @@ typedef struct Vp3DecodeContext {
int coded_fragment_list_index;
int pixel_addresses_initialized;
/* track which fragments have already been decoded; called 'fast'
* because this data structure avoids having to iterate through every
* fragment in coded_fragment_list; once a fragment has been fully
* decoded, it is removed from this list */
int *fast_fragment_list;
int fragment_list_y_head;
int fragment_list_c_head;
VLC dc_vlc[16];
VLC ac_vlc_1[16];
VLC ac_vlc_2[16];
@ -723,6 +731,25 @@ static int unpack_superblocks(Vp3DecodeContext *s, GetBitContext *gb)
/* end the list of coded C fragments */
s->last_coded_c_fragment = s->coded_fragment_list_index - 1;
for (i = 0; i < s->fragment_count - 1; i++) {
s->fast_fragment_list[i] = i + 1;
}
s->fast_fragment_list[s->fragment_count - 1] = -1;
if (s->last_coded_y_fragment == -1)
s->fragment_list_y_head = -1;
else {
s->fragment_list_y_head = s->first_coded_y_fragment;
s->fast_fragment_list[s->last_coded_y_fragment] = -1;
}
if (s->last_coded_c_fragment == -1)
s->fragment_list_c_head = -1;
else {
s->fragment_list_c_head = s->first_coded_c_fragment;
s->fast_fragment_list[s->last_coded_c_fragment] = -1;
}
return 0;
}
@ -1029,7 +1056,7 @@ static int unpack_block_qpis(Vp3DecodeContext *s, GetBitContext *gb)
*/
static int unpack_vlcs(Vp3DecodeContext *s, GetBitContext *gb,
VLC *table, int coeff_index,
int first_fragment, int last_fragment,
int y_plane,
int eob_run)
{
int i;
@ -1038,6 +1065,10 @@ static int unpack_vlcs(Vp3DecodeContext *s, GetBitContext *gb,
DCTELEM coeff = 0;
Vp3Fragment *fragment;
int bits_to_get;
int next_fragment;
int previous_fragment;
int fragment_num;
int *list_head;
/* local references to structure members to avoid repeated deferences */
uint8_t *perm= s->scantable.permutated;
@ -1045,20 +1076,26 @@ static int unpack_vlcs(Vp3DecodeContext *s, GetBitContext *gb,
Vp3Fragment *all_fragments = s->all_fragments;
uint8_t *coeff_counts = s->coeff_counts;
VLC_TYPE (*vlc_table)[2] = table->table;
int *fast_fragment_list = s->fast_fragment_list;
if ((first_fragment >= s->fragment_count) ||
(last_fragment >= s->fragment_count)) {
av_log(s->avctx, AV_LOG_ERROR, " vp3:unpack_vlcs(): bad fragment number (%d -> %d ?)\n",
first_fragment, last_fragment);
return 0;
if (y_plane) {
next_fragment = s->fragment_list_y_head;
list_head = &s->fragment_list_y_head;
} else {
next_fragment = s->fragment_list_c_head;
list_head = &s->fragment_list_c_head;
}
for (i = first_fragment; i <= last_fragment; i++) {
int fragment_num = coded_fragment_list[i];
i = next_fragment;
previous_fragment = -1; /* this indicates that the previous fragment is actually the list head */
while (i != -1) {
fragment_num = coded_fragment_list[i];
if (coeff_counts[fragment_num] > coeff_index)
if (coeff_counts[fragment_num] > coeff_index) {
previous_fragment = i;
i = fast_fragment_list[i];
continue;
}
fragment = &all_fragments[fragment_num];
if (!eob_run) {
@ -1091,10 +1128,20 @@ static int unpack_vlcs(Vp3DecodeContext *s, GetBitContext *gb,
s->next_coeff->next=NULL;
fragment->next_coeff= s->next_coeff++;
}
/* previous fragment is now this fragment */
previous_fragment = i;
} else {
coeff_counts[fragment_num] |= 128;
eob_run--;
/* remove this fragment from the list */
if (previous_fragment != -1)
fast_fragment_list[previous_fragment] = fast_fragment_list[i];
else
*list_head = fast_fragment_list[i];
/* previous fragment remains unchanged */
}
i = fast_fragment_list[i];
}
return eob_run;
@ -1123,14 +1170,14 @@ static int unpack_dct_coeffs(Vp3DecodeContext *s, GetBitContext *gb)
/* unpack the Y plane DC coefficients */
residual_eob_run = unpack_vlcs(s, gb, &s->dc_vlc[dc_y_table], 0,
s->first_coded_y_fragment, s->last_coded_y_fragment, residual_eob_run);
1, residual_eob_run);
/* reverse prediction of the Y-plane DC coefficients */
reverse_dc_prediction(s, 0, s->fragment_width, s->fragment_height);
/* unpack the C plane DC coefficients */
residual_eob_run = unpack_vlcs(s, gb, &s->dc_vlc[dc_c_table], 0,
s->first_coded_c_fragment, s->last_coded_c_fragment, residual_eob_run);
0, residual_eob_run);
/* reverse prediction of the C-plane DC coefficients */
if (!(s->avctx->flags & CODEC_FLAG_GRAY))
@ -1148,37 +1195,37 @@ static int unpack_dct_coeffs(Vp3DecodeContext *s, GetBitContext *gb)
/* unpack the group 1 AC coefficients (coeffs 1-5) */
for (i = 1; i <= 5; i++) {
residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_1[ac_y_table], i,
s->first_coded_y_fragment, s->last_coded_y_fragment, residual_eob_run);
1, residual_eob_run);
residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_1[ac_c_table], i,
s->first_coded_c_fragment, s->last_coded_c_fragment, residual_eob_run);
0, residual_eob_run);
}
/* unpack the group 2 AC coefficients (coeffs 6-14) */
for (i = 6; i <= 14; i++) {
residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_2[ac_y_table], i,
s->first_coded_y_fragment, s->last_coded_y_fragment, residual_eob_run);
1, residual_eob_run);
residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_2[ac_c_table], i,
s->first_coded_c_fragment, s->last_coded_c_fragment, residual_eob_run);
0, residual_eob_run);
}
/* unpack the group 3 AC coefficients (coeffs 15-27) */
for (i = 15; i <= 27; i++) {
residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_3[ac_y_table], i,
s->first_coded_y_fragment, s->last_coded_y_fragment, residual_eob_run);
1, residual_eob_run);
residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_3[ac_c_table], i,
s->first_coded_c_fragment, s->last_coded_c_fragment, residual_eob_run);
0, residual_eob_run);
}
/* unpack the group 4 AC coefficients (coeffs 28-63) */
for (i = 28; i <= 63; i++) {
residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_4[ac_y_table], i,
s->first_coded_y_fragment, s->last_coded_y_fragment, residual_eob_run);
1, residual_eob_run);
residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_4[ac_c_table], i,
s->first_coded_c_fragment, s->last_coded_c_fragment, residual_eob_run);
0, residual_eob_run);
}
return 0;
@ -1756,9 +1803,10 @@ static av_cold int vp3_decode_init(AVCodecContext *avctx)
s->coeff_counts = av_malloc(s->fragment_count * sizeof(*s->coeff_counts));
s->coeffs = av_malloc(s->fragment_count * sizeof(Coeff) * 65);
s->coded_fragment_list = av_malloc(s->fragment_count * sizeof(int));
s->fast_fragment_list = av_malloc(s->fragment_count * sizeof(int));
s->pixel_addresses_initialized = 0;
if (!s->superblock_coding || !s->all_fragments || !s->coeff_counts ||
!s->coeffs || !s->coded_fragment_list) {
!s->coeffs || !s->coded_fragment_list || !s->fast_fragment_list) {
vp3_decode_end(avctx);
return -1;
}
@ -2057,6 +2105,7 @@ static av_cold int vp3_decode_end(AVCodecContext *avctx)
av_free(s->coeff_counts);
av_free(s->coeffs);
av_free(s->coded_fragment_list);
av_free(s->fast_fragment_list);
av_free(s->superblock_fragments);
av_free(s->superblock_macroblocks);
av_free(s->macroblock_fragments);