Handle AVID MJPEG streams directly in the MJPEG decoder.

AVID streams - currently handled by the AVRN decoder - can be (depending
on extradata contents) either MJPEG or raw video. To decode the MJPEG
variant, the AVRN decoder currently instantiates a MJPEG decoder
internally and forwards decoded frames to the caller (possibly after
cropping them).

This is suboptimal, because the AVRN decoder does not forward all the
features of the internal MJPEG decoder, such as direct rendering.
Handling such forwarding in a full and generic manner would be quite
hard, so it is simpler to just handle those streams in the MJPEG decoder
directly.

The AVRN decoder, which now handles only the raw streams, can now be
marked as supporting direct rendering.

This also removes the last remaining internal use of the obsolete
decoding API.

configure

@@ -2688,7 +2688,6 @@ atrac3p_decoder_select="mdct sinewin"
 atrac3pal_decoder_select="mdct sinewin"
 atrac9_decoder_select="mdct"
 av1_decoder_select="cbs_av1"
-avrn_decoder_select="mjpeg_decoder"
 bink_decoder_select="blockdsp hpeldsp"
 binkaudio_dct_decoder_select="mdct rdft dct sinewin wma_freqs"
 binkaudio_rdft_decoder_select="mdct rdft sinewin wma_freqs"

libavcodec/avrndec.c

@@ -24,8 +24,6 @@
 #include "libavutil/imgutils.h"
 
 typedef struct {
-    AVCodecContext *mjpeg_avctx;
-    int is_mjpeg;
     int interlace;
     int tff;
 } AVRnContext;
@@ -35,42 +33,6 @@ static av_cold int init(AVCodecContext *avctx)
     AVRnContext *a = avctx->priv_data;
     int ret;
 
-    // Support "Resolution 1:1" for Avid AVI Codec
-    a->is_mjpeg = avctx->extradata_size < 31 || memcmp(&avctx->extradata[28], "1:1", 3);
-
-    if(!a->is_mjpeg && avctx->lowres) {
-        av_log(avctx, AV_LOG_ERROR, "lowres is not possible with rawvideo\n");
-        return AVERROR(EINVAL);
-    }
-
-    if(a->is_mjpeg) {
-        const AVCodec *codec = avcodec_find_decoder(AV_CODEC_ID_MJPEG);
-        AVDictionary *thread_opt = NULL;
-        if (!codec) {
-            av_log(avctx, AV_LOG_ERROR, "MJPEG codec not found\n");
-            return AVERROR_DECODER_NOT_FOUND;
-        }
-
-        a->mjpeg_avctx = avcodec_alloc_context3(codec);
-        if (!a->mjpeg_avctx)
-            return AVERROR(ENOMEM);
-
-        av_dict_set(&thread_opt, "threads", "1", 0); // Is this needed ?
-        a->mjpeg_avctx->refcounted_frames = 1;
-        a->mjpeg_avctx->flags = avctx->flags;
-        a->mjpeg_avctx->idct_algo = avctx->idct_algo;
-        a->mjpeg_avctx->lowres = avctx->lowres;
-        a->mjpeg_avctx->width = avctx->width;
-        a->mjpeg_avctx->height = avctx->height;
-
-        if ((ret = avcodec_open2(a->mjpeg_avctx, codec, &thread_opt)) < 0) {
-            av_log(avctx, AV_LOG_ERROR, "MJPEG codec failed to open\n");
-        }
-        av_dict_free(&thread_opt);
-
-        return ret;
-    }
-
     if ((ret = av_image_check_size(avctx->width, avctx->height, 0, avctx)) < 0)
         return ret;
 
@@ -87,15 +49,6 @@ static av_cold int init(AVCodecContext *avctx)
     return 0;
 }
 
-static av_cold int end(AVCodecContext *avctx)
-{
-    AVRnContext *a = avctx->priv_data;
-
-    avcodec_free_context(&a->mjpeg_avctx);
-
-    return 0;
-}
-
 static int decode_frame(AVCodecContext *avctx, void *data,
                         int *got_frame, AVPacket *avpkt)
 {
@@ -105,28 +58,6 @@ static int decode_frame(AVCodecContext *avctx, void *data,
     int buf_size       = avpkt->size;
     int y, ret, true_height;
 
-    if(a->is_mjpeg) {
-        ret = avcodec_decode_video2(a->mjpeg_avctx, data, got_frame, avpkt);
-
-        if (ret >= 0 && *got_frame && avctx->width <= p->width && avctx->height <= p->height) {
-            int shift = p->height - avctx->height;
-            int subsample_h, subsample_v;
-
-            av_pix_fmt_get_chroma_sub_sample(p->format, &subsample_h, &subsample_v);
-
-            p->data[0] += p->linesize[0] * shift;
-            if (p->data[2]) {
-                p->data[1] += p->linesize[1] * (shift>>subsample_v);
-                p->data[2] += p->linesize[2] * (shift>>subsample_v);
-            }
-
-            p->width  = avctx->width;
-            p->height = avctx->height;
-        }
-        avctx->pix_fmt = a->mjpeg_avctx->pix_fmt;
-        return ret;
-    }
-
     true_height    = buf_size / (2*avctx->width);
 
     if(buf_size < 2*avctx->width * avctx->height) {
@@ -165,8 +96,8 @@ AVCodec ff_avrn_decoder = {
     .id             = AV_CODEC_ID_AVRN,
     .priv_data_size = sizeof(AVRnContext),
     .init           = init,
-    .close          = end,
     .decode         = decode_frame,
     .max_lowres     = 3,
+    .capabilities   = AV_CODEC_CAP_DR1,
     .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
 };

libavcodec/mjpegdec.c

@@ -450,6 +450,11 @@ int ff_mjpeg_decode_sof(MJpegDecodeContext *s)
         size_change = 0;
     }
 
+    if ((s->avctx->codec_tag == MKTAG('A', 'V', 'R', 'n') ||
+         s->avctx->codec_tag == MKTAG('A', 'V', 'D', 'J')) &&
+        s->orig_height < s->avctx->height)
+        s->avctx->height = s->orig_height;
+
     if (s->avctx->codec_id == AV_CODEC_ID_SMVJPEG) {
         s->avctx->height = s->avctx->coded_height / s->smv_frames_per_jpeg;
         if (s->avctx->height <= 0)
@@ -2855,6 +2860,12 @@ the_end:
             return ret;
         }
     }
+    if ((avctx->codec_tag == MKTAG('A', 'V', 'R', 'n') ||
+         avctx->codec_tag == MKTAG('A', 'V', 'D', 'J')) &&
+        avctx->coded_height > s->orig_height) {
+        frame->height   = avctx->coded_height;
+        frame->crop_top = frame->height - s->orig_height;
+    }
 
     ret = 0;
 

libavcodec/version.h

@@ -29,7 +29,7 @@
 
 #define LIBAVCODEC_VERSION_MAJOR  58
 #define LIBAVCODEC_VERSION_MINOR 125
-#define LIBAVCODEC_VERSION_MICRO 100
+#define LIBAVCODEC_VERSION_MICRO 101
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
                                                LIBAVCODEC_VERSION_MINOR, \

libavformat/avidec.c

@@ -838,6 +838,12 @@ static int avi_read_header(AVFormatContext *s)
                         st->codecpar->codec_tag == MKTAG('H', '2', '6', '5'))
                         st->need_parsing = AVSTREAM_PARSE_FULL;
 
+                    if (st->codecpar->codec_id  == AV_CODEC_ID_AVRN &&
+                        st->codecpar->codec_tag == MKTAG('A', 'V', 'R', 'n') &&
+                        (st->codecpar->extradata_size < 31 ||
+                          memcmp(&st->codecpar->extradata[28], "1:1", 3)))
+                        st->codecpar->codec_id = AV_CODEC_ID_MJPEG;
+
                     if (st->codecpar->codec_tag == 0 && st->codecpar->height > 0 &&
                         st->codecpar->extradata_size < 1U << 30) {
                         st->codecpar->extradata_size += 9;

libavformat/isom_tags.c

@@ -69,8 +69,8 @@ const AVCodecTag ff_codec_movvideo_tags[] = {
 
     { AV_CODEC_ID_MJPEG,  MKTAG('j', 'p', 'e', 'g') }, /* PhotoJPEG */
     { AV_CODEC_ID_MJPEG,  MKTAG('m', 'j', 'p', 'a') }, /* Motion-JPEG (format A) */
-    { AV_CODEC_ID_AVRN ,  MKTAG('A', 'V', 'D', 'J') }, /* MJPEG with alpha-channel (AVID JFIF meridien compressed) */
-/*  { AV_CODEC_ID_MJPEG,  MKTAG('A', 'V', 'R', 'n') }, *//* MJPEG with alpha-channel (AVID ABVB/Truevision NuVista) */
+    { AV_CODEC_ID_MJPEG,  MKTAG('A', 'V', 'D', 'J') }, /* MJPEG with alpha-channel (AVID JFIF meridien compressed) */
+    { AV_CODEC_ID_MJPEG,  MKTAG('A', 'V', 'R', 'n') }, /* MJPEG with alpha-channel (AVID ABVB/Truevision NuVista) */
     { AV_CODEC_ID_MJPEG,  MKTAG('d', 'm', 'b', '1') }, /* Motion JPEG OpenDML */
     { AV_CODEC_ID_MJPEGB, MKTAG('m', 'j', 'p', 'b') }, /* Motion-JPEG (format B) */
 

tests/fate/video.mak

@@ -46,7 +46,7 @@ fate-auravision-v2: CMD = framecrc -i $(TARGET_SAMPLES)/auravision/salma-hayek-i
 FATE_VIDEO-$(call DEMDEC, AVI, AVRN) += fate-avid-interlaced
 fate-avid-interlaced: CMD = framecrc -i $(TARGET_SAMPLES)/avid/avid_ntsc_interlaced.avi
 
-FATE_VIDEO-$(call DEMDEC, MOV, AVRN) += fate-avid-meridian
+FATE_VIDEO-$(call DEMDEC, MOV, MJPEG) += fate-avid-meridian
 fate-avid-meridian: CMD = framecrc -i $(TARGET_SAMPLES)/avid/avidmeridianntsc.mov
 
 FATE_VIDEO-$(call DEMDEC, BETHSOFTVID, BETHSOFTVID) += fate-bethsoft-vid