[FFmpeg-devel] [PATCH] mjpeg: Add support for ICC side data

[Derek Buitenhuis]

JPEGs store embedded profiles under the APP2 marker, signified
with a "ICC_PROFILE" null-terminated string header, and can be
split across multiple APP2 markers, out of order.

This patch currently assumes one single ICC profile for the
whole context, i.e. a single JPEG input file. This likely does
not work for MJPEG files with embedded ICC profiles, but I could
not find a real, exisiting file, that had that.

Signed-off-by: Derek Buitenhuis <derek.buitenhuis at gmail.com>
---
 libavcodec/mjpegdec.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++++++
 libavcodec/mjpegdec.h |  5 +++
 2 files changed, 95 insertions(+)

diff --git a/libavcodec/mjpegdec.c b/libavcodec/mjpegdec.c
index 387ceadf..8be5e01 100644
--- a/libavcodec/mjpegdec.c
+++ b/libavcodec/mjpegdec.c
@@ -1901,6 +1901,67 @@ static int mjpeg_decode_app(MJpegDecodeContext *s)
         }
     }
 
+    if (s->start_code == APP2 && id == AV_RB32("ICC_") && len >= 10) {
+        int id2;
+        unsigned seqno;
+        unsigned nummarkers;
+
+        id   = get_bits_long(&s->gb, 32);
+        id2  = get_bits_long(&s->gb, 24);
+        len -= 7;
+        if (id != AV_RB32("PROF") || id2 != AV_RB24("ILE")) {
+            av_log(s->avctx, AV_LOG_WARNING, "Invalid ICC_PROFILE header in APP2\n");
+            goto out;
+        }
+
+        skip_bits(&s->gb, 8);
+        seqno  = get_bits(&s->gb, 8);
+        len   -= 2;
+        if (seqno == 0) {
+            av_log(s->avctx, AV_LOG_WARNING, "Invalid sequence number in APP2\n");
+            goto out;
+        }
+
+        nummarkers  = get_bits(&s->gb, 8);
+        len        -= 1;
+        if (nummarkers == 0) {
+            av_log(s->avctx, AV_LOG_WARNING, "Invalid number of markers coded in APP2\n");
+            goto out;
+        } else if (s->iccnum != 0 && nummarkers != s->iccnum) {
+            av_log(s->avctx, AV_LOG_WARNING, "Mistmatch in coded number of ICC markers between markers\n");
+            goto out;
+        } else if (seqno > nummarkers) {
+            av_log(s->avctx, AV_LOG_WARNING, "Mismatching sequence number and coded number of ICC markers\n");
+            goto out;
+        }
+
+        /* Allocate if this is the first APP2 we've seen. */
+        if (s->iccnum == 0) {
+            s->iccdata     = av_mallocz(nummarkers * sizeof(*(s->iccdata)));
+            s->iccdatalens = av_mallocz(nummarkers * sizeof(*(s->iccdatalens)));
+            if (!s->iccdata || !s->iccdatalens) {
+                av_log(s->avctx, AV_LOG_ERROR, "Could not allocate ICC data arrays\n");
+                return AVERROR(ENOMEM);
+            }
+            s->iccnum = nummarkers;
+        }
+
+        s->iccdatalens[seqno - 1]  = len;
+        s->iccdata[seqno - 1]      = av_malloc(len);
+        if (!s->iccdata[seqno - 1]) {
+            av_log(s->avctx, AV_LOG_ERROR, "Could not allocate ICC data buffer\n");
+            return AVERROR(ENOMEM);
+        }
+
+        memcpy(s->iccdata[seqno - 1], align_get_bits(&s->gb), len);
+        skip_bits(&s->gb, len << 3);
+        len = 0;
+        s->iccread++;
+
+        if (s->iccread > s->iccnum)
+            av_log(s->avctx, AV_LOG_WARNING, "Read more ICC markers than are supposed to be coded\n");
+    }
+
 out:
     /* slow but needed for extreme adobe jpegs */
     if (len < 0)
@@ -2509,6 +2570,29 @@ the_end:
         av_freep(&s->stereo3d);
     }
 
+    if (s->iccnum != 0 && s->iccnum == s->iccread) {
+        AVFrameSideData *sd;
+        size_t offset = 0;
+        int total_size = 0;
+        int i;
+
+        /* Sum size of all parts. */
+        for (i = 0; i < s->iccnum; i++)
+            total_size += s->iccdatalens[i];
+
+        sd = av_frame_new_side_data(data, AV_FRAME_DATA_ICC_PROFILE, total_size);
+        if (!sd) {
+            av_log(s->avctx, AV_LOG_ERROR, "Could not allocate frame side data\n");
+            return AVERROR(ENOMEM);
+        }
+
+        /* Reassemble the parts, which are now in-order. */
+        for (i = 0; i < s->iccnum; i++) {
+            memcpy(sd->data + offset, s->iccdata[i], s->iccdatalens[i]);
+            offset += s->iccdatalens[i];
+        }
+    }
+
     av_dict_copy(&((AVFrame *) data)->metadata, s->exif_metadata, 0);
     av_dict_free(&s->exif_metadata);
 
@@ -2548,6 +2632,12 @@ av_cold int ff_mjpeg_decode_end(AVCodecContext *avctx)
         av_freep(&s->last_nnz[i]);
     }
     av_dict_free(&s->exif_metadata);
+
+    if (s->iccdata)
+        for (i = 0; i < s->iccnum; i++)
+            av_freep(&s->iccdata[i]);
+    av_freep(&s->iccdata);
+    av_freep(&s->iccdatalens);
     return 0;
 }
 
diff --git a/libavcodec/mjpegdec.h b/libavcodec/mjpegdec.h
index 024cedc..2bc69fa 100644
--- a/libavcodec/mjpegdec.h
+++ b/libavcodec/mjpegdec.h
@@ -130,6 +130,11 @@ typedef struct MJpegDecodeContext {
     AVStereo3D *stereo3d; ///!< stereoscopic information (cached, since it is read before frame allocation)
 
     const AVPixFmtDescriptor *pix_desc;
+
+    uint8_t **iccdata;
+    int *iccdatalens;
+    int iccnum;
+    int iccread;
 } MJpegDecodeContext;
 
 int ff_mjpeg_decode_init(AVCodecContext *avctx);
-- 
1.8.3.1