avcodec/mpegvideo_dec: Always initialize IDCTDSPContext during init

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@outlook.com>

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);
 

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);

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++) {

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
 }
 
@@ -84,7 +85,6 @@ 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;
         }

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;
 

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;
 

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);