[FFmpeg-devel] [PATCH 7/8] avcodec/mpegvideo_dec: Always initialize IDCTDSPContext during init

Andreas Rheinhardt andreas.rheinhardt at outlook.com
Mon Oct 2 13:52:01 EEST 2023


It has currently not been done for H263, H263P and MPEG4.
Doing so avoids having to initialize the IDCT permutation
lateron when decoding packets in order to be able to parse
a quant matrix; it means that every mpegvideo decoder always
has an initialized IDCTDSPContext after init.
Initializing is done generically in ff_mpv_decode_init().

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
---
 libavcodec/h261dec.c       | 1 -
 libavcodec/h263dec.c       | 5 -----
 libavcodec/mpeg12dec.c     | 2 --
 libavcodec/mpegvideo_dec.c | 2 +-
 libavcodec/rv10.c          | 1 -
 libavcodec/rv34.c          | 1 -
 libavcodec/vc1dec.c        | 1 -
 7 files changed, 1 insertion(+), 12 deletions(-)

diff --git a/libavcodec/h261dec.c b/libavcodec/h261dec.c
index c41b96c3c7..6cdf11f822 100644
--- a/libavcodec/h261dec.c
+++ b/libavcodec/h261dec.c
@@ -94,7 +94,6 @@ static av_cold int h261_decode_init(AVCodecContext *avctx)
     avctx->pix_fmt = AV_PIX_FMT_YUV420P;
 
     h->gob_start_code_skipped = 0;
-    ff_mpv_idct_init(s);
 
     ff_thread_once(&init_static_once, h261_decode_init_static);
 
diff --git a/libavcodec/h263dec.c b/libavcodec/h263dec.c
index 9f63f1a7cb..544d32b682 100644
--- a/libavcodec/h263dec.c
+++ b/libavcodec/h263dec.c
@@ -128,7 +128,6 @@ av_cold int ff_h263_decode_init(AVCodecContext *avctx)
         avctx->codec->id != AV_CODEC_ID_H263P &&
         avctx->codec->id != AV_CODEC_ID_MPEG4) {
         avctx->pix_fmt = h263_get_format(avctx);
-        ff_mpv_idct_init(s);
         if ((ret = ff_mpv_common_init(s)) < 0)
             return ret;
     }
@@ -459,10 +458,6 @@ retry:
     if (ret < 0)
         return ret;
 
-    if (!s->context_initialized)
-        // we need the idct permutation for reading a custom matrix
-        ff_mpv_idct_init(s);
-
     /* let's go :-) */
     if (CONFIG_WMV2_DECODER && s->msmpeg4_version == 5) {
         ret = ff_wmv2_decode_picture_header(s);
diff --git a/libavcodec/mpeg12dec.c b/libavcodec/mpeg12dec.c
index d2dbcd5b61..c0f1e8763b 100644
--- a/libavcodec/mpeg12dec.c
+++ b/libavcodec/mpeg12dec.c
@@ -1057,7 +1057,6 @@ static av_cold int mpeg_decode_init(AVCodecContext *avctx)
         avctx->coded_width = avctx->coded_height = 0; // do not trust dimensions from input
     ff_mpv_decode_init(s2, avctx);
 
-    ff_mpv_idct_init(s2);
     ff_mpeg12_init_vlcs();
 
     s2->chroma_format              = 1;
@@ -3048,7 +3047,6 @@ static av_cold int ipu_decode_init(AVCodecContext *avctx)
     avctx->pix_fmt = AV_PIX_FMT_YUV420P;
 
     ff_mpv_decode_init(m, avctx);
-    ff_mpv_idct_init(m);
     ff_mpeg12_init_vlcs();
 
     for (int i = 0; i < 64; i++) {
diff --git a/libavcodec/mpegvideo_dec.c b/libavcodec/mpegvideo_dec.c
index 3f173a9feb..39d1282252 100644
--- a/libavcodec/mpegvideo_dec.c
+++ b/libavcodec/mpegvideo_dec.c
@@ -54,6 +54,7 @@ void ff_mpv_decode_init(MpegEncContext *s, AVCodecContext *avctx)
     /* convert fourcc to upper case */
     s->codec_tag       = ff_toupper4(avctx->codec_tag);
 
+    ff_mpv_idct_init(s);
     ff_h264chroma_init(&s->h264chroma, 8); //for lowres
 }
 
@@ -82,7 +83,6 @@ int ff_mpeg_update_thread_context(AVCodecContext *dst,
         s->bitstream_buffer_size = s->allocated_bitstream_buffer_size = 0;
 
         if (s1->context_initialized) {
-            ff_mpv_idct_init(s);
             if ((err = ff_mpv_common_init(s)) < 0)
                 return err;
         }
diff --git a/libavcodec/rv10.c b/libavcodec/rv10.c
index 6abceade4e..fbecfdae9f 100644
--- a/libavcodec/rv10.c
+++ b/libavcodec/rv10.c
@@ -420,7 +420,6 @@ static av_cold int rv10_decode_init(AVCodecContext *avctx)
 
     avctx->pix_fmt = AV_PIX_FMT_YUV420P;
 
-    ff_mpv_idct_init(s);
     if ((ret = ff_mpv_common_init(s)) < 0)
         return ret;
 
diff --git a/libavcodec/rv34.c b/libavcodec/rv34.c
index e9660bb457..152c62fa07 100644
--- a/libavcodec/rv34.c
+++ b/libavcodec/rv34.c
@@ -1498,7 +1498,6 @@ av_cold int ff_rv34_decode_init(AVCodecContext *avctx)
     avctx->has_b_frames = 1;
     s->low_delay = 0;
 
-    ff_mpv_idct_init(s);
     if ((ret = ff_mpv_common_init(s)) < 0)
         return ret;
 
diff --git a/libavcodec/vc1dec.c b/libavcodec/vc1dec.c
index 449d2fea5e..a4f2d30e22 100644
--- a/libavcodec/vc1dec.c
+++ b/libavcodec/vc1dec.c
@@ -431,7 +431,6 @@ av_cold int ff_vc1_decode_init(AVCodecContext *avctx)
         return ret;
 
     ff_mpv_decode_init(s, avctx);
-    ff_mpv_idct_init(s);
 
     avctx->pix_fmt = vc1_get_format(avctx);
 
-- 
2.34.1



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