From 098523eb28df3a1cf4bddca088d80d5cbd2b9a1f Mon Sep 17 00:00:00 2001 From: Mike Melanson Date: Wed, 2 Dec 2009 02:30:15 +0000 Subject: [PATCH] Use a list to track which fragments coded in this frame still have 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 --- libavcodec/vp3.c | 91 +++++++++++++++++++++++++++++++++++++----------- 1 file changed, 70 insertions(+), 21 deletions(-) diff --git a/libavcodec/vp3.c b/libavcodec/vp3.c index 60b84f0b5f..292f01045e 100644 --- a/libavcodec/vp3.c +++ b/libavcodec/vp3.c @@ -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);