From 36b5f71b1fbc4757e3b8f1f5fe666553bfb4ce1f Mon Sep 17 00:00:00 2001 From: Andreas Rheinhardt Date: Sun, 24 Sep 2023 19:07:50 +0200 Subject: [PATCH] avcodec/msmpeg4dec: Avoid superfluous VLC structures For all VLCs here, the number of bits of the VLC is write-only, because it is hardcoded at the call site. Therefore one can replace these VLC structures with the only thing that is actually used: The pointer to the VLCElem table. And in some cases one can even avoid this. Signed-off-by: Andreas Rheinhardt --- libavcodec/msmpeg4data.h | 2 +- libavcodec/msmpeg4dec.c | 93 +++++++++++++++++++++------------------- libavcodec/msmpeg4dec.h | 4 +- libavcodec/wmv2dec.c | 4 +- 4 files changed, 53 insertions(+), 50 deletions(-) diff --git a/libavcodec/msmpeg4data.h b/libavcodec/msmpeg4data.h index 26ee960f82..aa4ca86a05 100644 --- a/libavcodec/msmpeg4data.h +++ b/libavcodec/msmpeg4data.h @@ -44,7 +44,7 @@ typedef struct MVTable { const uint8_t *table_mvx; const uint8_t *table_mvy; uint16_t *table_mv_index; /* encoding: convert mv to index in table_mv */ - VLC vlc; /* decoding: vlc */ + const VLCElem *vlc; /* decoding: vlc */ } MVTable; FF_VISIBILITY_PUSH_HIDDEN diff --git a/libavcodec/msmpeg4dec.c b/libavcodec/msmpeg4dec.c index 716fc13529..5b10d8f225 100644 --- a/libavcodec/msmpeg4dec.c +++ b/libavcodec/msmpeg4dec.c @@ -63,12 +63,12 @@ static inline int msmpeg4v1_pred_dc(MpegEncContext * s, int n, /****************************************/ /* decoding stuff */ -VLC ff_mb_non_intra_vlc[4]; -static VLC v2_dc_lum_vlc; -static VLC v2_dc_chroma_vlc; -static VLC v2_intra_cbpc_vlc; -static VLC v2_mb_type_vlc; -VLC ff_inter_intra_vlc; +const VLCElem *ff_mb_non_intra_vlc[4]; +static VLCElem v2_dc_lum_vlc[1472]; +static VLCElem v2_dc_chroma_vlc[1506]; +static VLCElem v2_intra_cbpc_vlc[8]; +static VLCElem v2_mb_type_vlc[128]; +VLCElem ff_inter_intra_vlc[8]; /* This is identical to H.263 except that its range is multiplied by 2. */ static int msmpeg4v2_decode_motion(MpegEncContext * s, int pred, int f_code) @@ -125,7 +125,7 @@ static int msmpeg4v12_decode_mb(MpegEncContext *s, int16_t block[6][64]) } if(s->msmpeg4_version==2) - code = get_vlc2(&s->gb, v2_mb_type_vlc.table, V2_MB_TYPE_VLC_BITS, 1); + code = get_vlc2(&s->gb, v2_mb_type_vlc, V2_MB_TYPE_VLC_BITS, 1); else code = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc, INTER_MCBPC_VLC_BITS, 2); if(code<0 || code>7){ @@ -139,7 +139,7 @@ static int msmpeg4v12_decode_mb(MpegEncContext *s, int16_t block[6][64]) } else { s->mb_intra = 1; if(s->msmpeg4_version==2) - cbp= get_vlc2(&s->gb, v2_intra_cbpc_vlc.table, V2_INTRA_CBPC_VLC_BITS, 1); + cbp = get_vlc2(&s->gb, v2_intra_cbpc_vlc, V2_INTRA_CBPC_VLC_BITS, 1); else cbp = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc, INTRA_MCBPC_VLC_BITS, 2); if(cbp<0 || cbp>3){ @@ -230,7 +230,7 @@ static int msmpeg4v34_decode_mb(MpegEncContext *s, int16_t block[6][64]) } } - code = get_vlc2(&s->gb, ff_mb_non_intra_vlc[DEFAULT_INTER_INDEX].table, MB_NON_INTRA_VLC_BITS, 3); + code = get_vlc2(&s->gb, ff_mb_non_intra_vlc[DEFAULT_INTER_INDEX], MB_NON_INTRA_VLC_BITS, 3); //s->mb_intra = (code & 0x40) ? 0 : 1; s->mb_intra = (~code & 0x40) >> 6; @@ -271,7 +271,7 @@ static int msmpeg4v34_decode_mb(MpegEncContext *s, int16_t block[6][64]) s->ac_pred = get_bits1(&s->gb); *mb_type_ptr = MB_TYPE_INTRA; if(s->inter_intra_pred){ - s->h263_aic_dir= get_vlc2(&s->gb, ff_inter_intra_vlc.table, INTER_INTRA_VLC_BITS, 1); + s->h263_aic_dir= get_vlc2(&s->gb, ff_inter_intra_vlc, INTER_INTRA_VLC_BITS, 1); ff_dlog(s, "%d%d %d %d/", s->ac_pred, s->h263_aic_dir, s->mb_x, s->mb_y); } @@ -296,6 +296,8 @@ static int msmpeg4v34_decode_mb(MpegEncContext *s, int16_t block[6][64]) /* init all vlc decoding tables */ static av_cold void msmpeg4_decode_init_static(void) { + static VLCElem vlc_buf[3714 + 2694 + 1636 + 2648 + 1532 + 2488]; + VLCInitState state = VLC_INIT_STATE(vlc_buf); MVTable *mv; INIT_FIRST_VLC_RL(ff_rl_table[0], 642); @@ -308,43 +310,44 @@ static av_cold void msmpeg4_decode_init_static(void) av_assert1(ff_h263_rl_inter.rl_vlc[0]); memcpy(ff_rl_table[5].rl_vlc, ff_h263_rl_inter.rl_vlc, sizeof(ff_rl_table[5].rl_vlc)); + VLC_INIT_STATIC_TABLE(v2_dc_lum_vlc, MSMP4_DC_VLC_BITS, 512, + &ff_v2_dc_lum_table[0][1], 8, 4, + &ff_v2_dc_lum_table[0][0], 8, 4, 0); + VLC_INIT_STATIC_TABLE(v2_dc_chroma_vlc, MSMP4_DC_VLC_BITS, 512, + &ff_v2_dc_chroma_table[0][1], 8, 4, + &ff_v2_dc_chroma_table[0][0], 8, 4, 0); + + VLC_INIT_STATIC_TABLE(v2_intra_cbpc_vlc, V2_INTRA_CBPC_VLC_BITS, 4, + &ff_v2_intra_cbpc[0][1], 2, 1, + &ff_v2_intra_cbpc[0][0], 2, 1, 0); + VLC_INIT_STATIC_TABLE(v2_mb_type_vlc, V2_MB_TYPE_VLC_BITS, 8, + &ff_v2_mb_type[0][1], 2, 1, + &ff_v2_mb_type[0][0], 2, 1, 0); + mv = &ff_mv_tables[0]; - VLC_INIT_STATIC(&mv->vlc, MV_VLC_BITS, MSMPEG4_MV_TABLES_NB_ELEMS + 1, - mv->table_mv_bits, 1, 1, - mv->table_mv_code, 2, 2, 3714); + mv->vlc = ff_vlc_init_tables_sparse(&state, MV_VLC_BITS, + MSMPEG4_MV_TABLES_NB_ELEMS + 1, + mv->table_mv_bits, 1, 1, + mv->table_mv_code, 2, 2, + NULL, 0, 0, 0); mv = &ff_mv_tables[1]; - VLC_INIT_STATIC(&mv->vlc, MV_VLC_BITS, MSMPEG4_MV_TABLES_NB_ELEMS + 1, - mv->table_mv_bits, 1, 1, - mv->table_mv_code, 2, 2, 2694); + mv->vlc = ff_vlc_init_tables_sparse(&state, MV_VLC_BITS, + MSMPEG4_MV_TABLES_NB_ELEMS + 1, + mv->table_mv_bits, 1, 1, + mv->table_mv_code, 2, 2, + NULL, 0, 0, 0); - VLC_INIT_STATIC(&v2_dc_lum_vlc, MSMP4_DC_VLC_BITS, 512, - &ff_v2_dc_lum_table[0][1], 8, 4, - &ff_v2_dc_lum_table[0][0], 8, 4, 1472); - VLC_INIT_STATIC(&v2_dc_chroma_vlc, MSMP4_DC_VLC_BITS, 512, - &ff_v2_dc_chroma_table[0][1], 8, 4, - &ff_v2_dc_chroma_table[0][0], 8, 4, 1506); - - VLC_INIT_STATIC(&v2_intra_cbpc_vlc, V2_INTRA_CBPC_VLC_BITS, 4, - &ff_v2_intra_cbpc[0][1], 2, 1, - &ff_v2_intra_cbpc[0][0], 2, 1, 8); - VLC_INIT_STATIC(&v2_mb_type_vlc, V2_MB_TYPE_VLC_BITS, 8, - &ff_v2_mb_type[0][1], 2, 1, - &ff_v2_mb_type[0][0], 2, 1, 128); - - for (unsigned i = 0, offset = 0; i < 4; i++) { - static VLCElem vlc_buf[1636 + 2648 + 1532 + 2488]; - ff_mb_non_intra_vlc[i].table = &vlc_buf[offset]; - ff_mb_non_intra_vlc[i].table_allocated = FF_ARRAY_ELEMS(vlc_buf) - offset; - vlc_init(&ff_mb_non_intra_vlc[i], MB_NON_INTRA_VLC_BITS, 128, - &ff_wmv2_inter_table[i][0][1], 8, 4, - &ff_wmv2_inter_table[i][0][0], 8, 4, - VLC_INIT_STATIC_OVERLONG); - offset += ff_mb_non_intra_vlc[i].table_size; + for (unsigned i = 0; i < 4; i++) { + ff_mb_non_intra_vlc[i] = + ff_vlc_init_tables_sparse(&state, MB_NON_INTRA_VLC_BITS, 128, + &ff_wmv2_inter_table[i][0][1], 8, 4, + &ff_wmv2_inter_table[i][0][0], 8, 4, + NULL, 0, 0, 0); } - VLC_INIT_STATIC(&ff_inter_intra_vlc, INTER_INTRA_VLC_BITS, 4, - &ff_table_inter_intra[0][1], 2, 1, - &ff_table_inter_intra[0][0], 2, 1, 8); + VLC_INIT_STATIC_TABLE(ff_inter_intra_vlc, INTER_INTRA_VLC_BITS, 4, + &ff_table_inter_intra[0][1], 2, 1, + &ff_table_inter_intra[0][0], 2, 1, 0); ff_msmp4_vc1_vlcs_init_once(); } @@ -572,9 +575,9 @@ static int msmpeg4_decode_dc(MpegEncContext * s, int n, int *dir_ptr) if(s->msmpeg4_version<=2){ if (n < 4) { - level = get_vlc2(&s->gb, v2_dc_lum_vlc.table, MSMP4_DC_VLC_BITS, 3); + level = get_vlc2(&s->gb, v2_dc_lum_vlc, MSMP4_DC_VLC_BITS, 3); } else { - level = get_vlc2(&s->gb, v2_dc_chroma_vlc.table, MSMP4_DC_VLC_BITS, 3); + level = get_vlc2(&s->gb, v2_dc_chroma_vlc, MSMP4_DC_VLC_BITS, 3); } if (level < 0) { av_log(s->avctx, AV_LOG_ERROR, "illegal dc vlc\n"); @@ -813,7 +816,7 @@ void ff_msmpeg4_decode_motion(MpegEncContext *s, int *mx_ptr, int *my_ptr) mv = &ff_mv_tables[s->mv_table_index]; - code = get_vlc2(&s->gb, mv->vlc.table, MV_VLC_BITS, 2); + code = get_vlc2(&s->gb, mv->vlc, MV_VLC_BITS, 2); if (code == MSMPEG4_MV_TABLES_NB_ELEMS) { mx = get_bits(&s->gb, 6); my = get_bits(&s->gb, 6); diff --git a/libavcodec/msmpeg4dec.h b/libavcodec/msmpeg4dec.h index ad41eea9d4..5daa7c6bc3 100644 --- a/libavcodec/msmpeg4dec.h +++ b/libavcodec/msmpeg4dec.h @@ -28,8 +28,8 @@ #define INTER_INTRA_VLC_BITS 3 #define MB_NON_INTRA_VLC_BITS 9 -extern VLC ff_mb_non_intra_vlc[4]; -extern VLC ff_inter_intra_vlc; +extern const VLCElem *ff_mb_non_intra_vlc[4]; +extern VLCElem ff_inter_intra_vlc[8]; int ff_msmpeg4_decode_init(AVCodecContext *avctx); int ff_msmpeg4_decode_picture_header(MpegEncContext *s); diff --git a/libavcodec/wmv2dec.c b/libavcodec/wmv2dec.c index 5395f21245..ab72590a8e 100644 --- a/libavcodec/wmv2dec.c +++ b/libavcodec/wmv2dec.c @@ -468,7 +468,7 @@ static int wmv2_decode_mb(MpegEncContext *s, int16_t block[6][64]) if (get_bits_left(&s->gb) <= 0) return AVERROR_INVALIDDATA; - code = get_vlc2(&s->gb, ff_mb_non_intra_vlc[w->cbp_table_index].table, + code = get_vlc2(&s->gb, ff_mb_non_intra_vlc[w->cbp_table_index], MB_NON_INTRA_VLC_BITS, 3); s->mb_intra = (~code & 0x40) >> 6; @@ -534,7 +534,7 @@ static int wmv2_decode_mb(MpegEncContext *s, int16_t block[6][64]) show_bits(&s->gb, 24)); s->ac_pred = get_bits1(&s->gb); if (s->inter_intra_pred) { - s->h263_aic_dir = get_vlc2(&s->gb, ff_inter_intra_vlc.table, + s->h263_aic_dir = get_vlc2(&s->gb, ff_inter_intra_vlc, INTER_INTRA_VLC_BITS, 1); ff_dlog(s->avctx, "%d%d %d %d/", s->ac_pred, s->h263_aic_dir, s->mb_x, s->mb_y);