From 03517b4743d2d5d8d50d9b75001c459ca011b7e6 Mon Sep 17 00:00:00 2001 From: Andreas Rheinhardt Date: Sun, 2 Jun 2024 07:22:48 +0200 Subject: [PATCH] avcodec/mpegvideo_dec: Set dct_unquantize ptrs only once when possible Everything except dct_unquantize_intra for MPEG-4 need only be set once. Signed-off-by: Andreas Rheinhardt Signed-off-by: Paul B Mahol --- libavcodec/h263dec.c | 8 ++++++++ libavcodec/mpegvideo_dec.c | 21 +++++++-------------- 2 files changed, 15 insertions(+), 14 deletions(-) diff --git a/libavcodec/h263dec.c b/libavcodec/h263dec.c index eee7978452..666675fcf1 100644 --- a/libavcodec/h263dec.c +++ b/libavcodec/h263dec.c @@ -110,6 +110,9 @@ av_cold int ff_h263_decode_init(AVCodecContext *avctx) avctx->chroma_sample_location = AVCHROMA_LOC_CENTER; break; case AV_CODEC_ID_MPEG4: + // dct_unquantize_inter is only used with MPEG-2 quantizers, + // so we can already set dct_unquantize_inter here once and for all. + s->dct_unquantize_inter = s->dct_unquantize_mpeg2_inter; break; case AV_CODEC_ID_MSMPEG4V1: s->h263_pred = 1; @@ -523,6 +526,11 @@ retry: goto retry; if (s->studio_profile != (s->idsp.idct == NULL)) ff_mpv_idct_init(s); + if (s->mpeg_quant) { + s->dct_unquantize_intra = s->dct_unquantize_mpeg2_intra; + } else { + s->dct_unquantize_intra = s->dct_unquantize_h263_intra; + } } /* After H.263 & MPEG-4 header decode we have the height, width, diff --git a/libavcodec/mpegvideo_dec.c b/libavcodec/mpegvideo_dec.c index 0a50cfac5b..ad35505819 100644 --- a/libavcodec/mpegvideo_dec.c +++ b/libavcodec/mpegvideo_dec.c @@ -59,6 +59,13 @@ int ff_mpv_decode_init(MpegEncContext *s, AVCodecContext *avctx) s->codec_tag = ff_toupper4(avctx->codec_tag); ff_mpv_idct_init(s); + + // dct_unquantize defaults for H.261 and H.263; + // they might change on a per-frame basis for MPEG-4. + // Unused by the MPEG-1/2 decoders. + s->dct_unquantize_intra = s->dct_unquantize_h263_intra; + s->dct_unquantize_inter = s->dct_unquantize_h263_inter; + ff_h264chroma_init(&s->h264chroma, 8); //for lowres if (s->picture_pool) // VC-1 can call this multiple times @@ -393,20 +400,6 @@ int ff_mpv_frame_start(MpegEncContext *s, AVCodecContext *avctx) if (ret < 0) return ret; - /* set dequantizer, we can't do it during init as - * it might change for MPEG-4 and we can't do it in the header - * decode as init is not called for MPEG-4 there yet */ - if (s->mpeg_quant || s->codec_id == AV_CODEC_ID_MPEG2VIDEO) { - s->dct_unquantize_intra = s->dct_unquantize_mpeg2_intra; - s->dct_unquantize_inter = s->dct_unquantize_mpeg2_inter; - } else if (s->out_format == FMT_H263 || s->out_format == FMT_H261) { - s->dct_unquantize_intra = s->dct_unquantize_h263_intra; - s->dct_unquantize_inter = s->dct_unquantize_h263_inter; - } else { - s->dct_unquantize_intra = s->dct_unquantize_mpeg1_intra; - s->dct_unquantize_inter = s->dct_unquantize_mpeg1_inter; - } - if (s->avctx->debug & FF_DEBUG_NOMC) color_frame(s->cur_pic.ptr->f, 0x80);