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avcodec/mjpegdec: Read EXIF metadata in JPEG input.

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Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Thilo Borgmann
2013-08-12 19:36:08 +02:00
committed by Michael Niedermayer
parent ad0f7574ef
commit bb4e1b4cf9
4 changed files with 49 additions and 1 deletions
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46
libavcodec/mjpegdec.c
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@@ -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;
}