avcodec/mpegvideo_enc: Move initializing QpelDSPCtx to mpeg4videoenc.c

It is the only encoder supporting quarter samples.
This also allows to remove the qpeldsp dependency from
mpegvideo_enc.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

configure

@@ -2754,7 +2754,7 @@ mpegaudio_select="mpegaudiodsp mpegaudioheader"
 mpegaudiodsp_select="dct"
 mpegvideo_select="blockdsp hpeldsp idctdsp videodsp"
 mpegvideodec_select="h264chroma mpegvideo mpeg_er"
-mpegvideoenc_select="aandcttables fdctdsp me_cmp mpegvideo pixblockdsp qpeldsp"
+mpegvideoenc_select="aandcttables fdctdsp me_cmp mpegvideo pixblockdsp"
 msmpeg4dec_select="h263_decoder"
 msmpeg4enc_select="h263_encoder"
 vc1dsp_select="h264chroma qpeldsp startcode"
@@ -2893,7 +2893,7 @@ mpeg1video_encoder_select="mpegvideoenc"
 mpeg2video_decoder_select="mpegvideodec"
 mpeg2video_encoder_select="mpegvideoenc"
 mpeg4_decoder_select="h263_decoder mpeg4video_parser"
-mpeg4_encoder_select="h263_encoder"
+mpeg4_encoder_select="h263_encoder qpeldsp"
 msa1_decoder_select="mss34dsp"
 mscc_decoder_select="inflate_wrapper"
 msmpeg4v1_decoder_select="msmpeg4dec"

libavcodec/mpeg4videoenc.c

@@ -1287,6 +1287,7 @@ static av_cold int encode_init(AVCodecContext *avctx)
         return AVERROR(EINVAL);
     }
 
+    ff_qpeldsp_init(&s->qdsp);
     if ((ret = ff_mpv_encode_init(avctx)) < 0)
         return ret;
 

libavcodec/mpegvideo_enc.c

@@ -807,7 +807,6 @@ av_cold int ff_mpv_encode_init(AVCodecContext *avctx)
     ff_me_cmp_init(&s->mecc, avctx);
     ff_mpegvideoencdsp_init(&s->mpvencdsp, avctx);
     ff_pixblockdsp_init(&s->pdsp, avctx);
-    ff_qpeldsp_init(&s->qdsp);
 
     if (!(avctx->stats_out = av_mallocz(256))               ||
         !FF_ALLOCZ_TYPED_ARRAY(s->q_intra_matrix,          32) ||