@@ -14,6 +14,7 @@ version <next>

 - ffmpeg -t option can now be used for inputs, to limit the duration of

   data read from an input file

 - incomplete Voxware MetaSound decoder

+- read EXIF metadata from JPEG

 version 2.0:

@@ -267,7 +267,7 @@ OBJS-$(CONFIG_METASOUND_DECODER)       += metasound.o metasound_data.o \

                                           twinvq.o

 OBJS-$(CONFIG_MICRODVD_DECODER)        += microdvddec.o ass.o

 OBJS-$(CONFIG_MIMIC_DECODER)           += mimic.o

-OBJS-$(CONFIG_MJPEG_DECODER)           += mjpegdec.o mjpeg.o

+OBJS-$(CONFIG_MJPEG_DECODER)           += mjpegdec.o mjpeg.o exif.o tiff_common.o

 OBJS-$(CONFIG_MJPEG_ENCODER)           += mjpegenc.o mjpeg.o

 OBJS-$(CONFIG_MJPEGB_DECODER)          += mjpegbdec.o mjpegdec.o mjpeg.o

 OBJS-$(CONFIG_MLP_DECODER)             += mlpdec.o mlpdsp.o

@@ -39,6 +39,9 @@

 #include "mjpeg.h"

 #include "mjpegdec.h"

 #include "jpeglsdec.h"

+#include "tiff.h"

+#include "exif.h"

+#include "bytestream.h"

 static int build_vlc(VLC *vlc, const uint8_t *bits_table,

@@ -1493,6 +1496,43 @@ static int mjpeg_decode_app(MJpegDecodeContext *s)

         goto out;

     }

+    /* EXIF metadata */

+    if (s->start_code == APP1 && id == AV_RB32("Exif")) {

+        GetByteContext gbytes;

+        int ret, le, ifd_offset, bytes_read;

+        const uint8_t *aligned;

+

+        skip_bits(&s->gb, 16); // skip padding

+        len -= 2;

+

+        // init byte wise reading

+        aligned = align_get_bits(&s->gb);

+        bytestream2_init(&gbytes, aligned, len);

+

+        // read TIFF header

+        ret = ff_tdecode_header(&gbytes, &le, &ifd_offset);

+        if (ret) {

+            av_log(s->avctx, AV_LOG_ERROR, "mjpeg: invalid TIFF header in EXIF data\n");

+            return ret;

+        }

+

+        bytestream2_seek(&gbytes, ifd_offset, SEEK_SET);

+

+        // read 0th IFD and store the metadata

+        // (return values > 0 indicate the presence of subimage metadata)

+        ret = ff_exif_decode_ifd(s->avctx, &gbytes, le, 0, &s->exif_metadata);

+        if (ret < 0) {

+            av_log(s->avctx, AV_LOG_ERROR, "mjpeg: error decoding EXIF data\n");

+            return ret;

+        }

+

+        bytes_read = bytestream2_tell(&gbytes);

+        skip_bits(&s->gb, bytes_read << 3);

+        len -= bytes_read;

+

+        goto out;

+    }

+

     /* Apple MJPEG-A */

     if ((s->start_code == APP1) && (len > (0x28 - 8))) {

         id   = get_bits_long(&s->gb, 32);

@@ -1688,6 +1728,8 @@ int ff_mjpeg_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,

     int i, index;

     int ret = 0;

+    av_dict_free(&s->exif_metadata);

+

     buf_ptr = buf;

     buf_end = buf + buf_size;

     while (buf_ptr < buf_end) {

@@ -1916,6 +1958,9 @@ the_end:

         }

     }

+    av_dict_copy(avpriv_frame_get_metadatap(data), s->exif_metadata, 0);

+    av_dict_free(&s->exif_metadata);

+

     av_log(avctx, AV_LOG_DEBUG, "decode frame unused %td bytes\n",

            buf_end - buf_ptr);

 //  return buf_end - buf_ptr;

@@ -1942,6 +1987,7 @@ av_cold int ff_mjpeg_decode_end(AVCodecContext *avctx)

         av_freep(&s->blocks[i]);

         av_freep(&s->last_nnz[i]);

     }

+    av_dict_free(&s->exif_metadata);

     return 0;

 }

@@ -119,6 +119,7 @@ typedef struct MJpegDecodeContext {

     unsigned int ljpeg_buffer_size;

     int extern_huff;

+    AVDictionary *exif_metadata;

 } MJpegDecodeContext;

 int ff_mjpeg_decode_init(AVCodecContext *avctx);