[FFmpeg-devel] [Read EXIF metadata 1/5] Refactor TIFF tag related functions to share the code.
Thilo Borgmann
thilo.borgmann at googlemail.com
Tue Jul 30 20:32:40 CEST 2013
---
libavcodec/tiff.c | 134 +++++++++++++++++++++++++++++------------------------
libavcodec/tiff.h | 15 ++++++
2 files changed, 89 insertions(+), 60 deletions(-)
diff --git a/libavcodec/tiff.c b/libavcodec/tiff.c
index fdfa8f2..0076be3 100644
--- a/libavcodec/tiff.c
+++ b/libavcodec/tiff.c
@@ -70,13 +70,13 @@ typedef struct TiffContext {
TiffGeoTag *geotags;
} TiffContext;
-static unsigned tget_short(GetByteContext *gb, int le)
+unsigned tget_short(GetByteContext *gb, int le)
{
unsigned v = le ? bytestream2_get_le16(gb) : bytestream2_get_be16(gb);
return v;
}
-static unsigned tget_long(GetByteContext *gb, int le)
+unsigned tget_long(GetByteContext *gb, int le)
{
unsigned v = le ? bytestream2_get_le32(gb) : bytestream2_get_be32(gb);
return v;
@@ -271,9 +271,9 @@ static char *shorts2str(int16_t *sp, int count, const char *sep)
return ap0;
}
-static int add_doubles_metadata(int count,
+int tiff_add_doubles_metadata(int count,
const char *name, const char *sep,
- TiffContext *s, AVFrame *frame)
+ GetByteContext *gb, int le, AVDictionary
**metadata)
{
char *ap;
int i;
@@ -281,7 +281,7 @@ static int add_doubles_metadata(int count,
if (count >= INT_MAX / sizeof(int64_t) || count <= 0)
return AVERROR_INVALIDDATA;
- if (bytestream2_get_bytes_left(&s->gb) < count * sizeof(int64_t))
+ if (bytestream2_get_bytes_left(gb) < count * sizeof(int64_t))
return AVERROR_INVALIDDATA;
dp = av_malloc(count * sizeof(double));
@@ -289,17 +289,18 @@ static int add_doubles_metadata(int count,
return AVERROR(ENOMEM);
for (i = 0; i < count; i++)
- dp[i] = tget_double(&s->gb, s->le);
+ dp[i] = tget_double(gb, le);
ap = doubles2str(dp, count, sep);
av_freep(&dp);
if (!ap)
return AVERROR(ENOMEM);
- av_dict_set(avpriv_frame_get_metadatap(frame), name, ap,
AV_DICT_DONT_STRDUP_VAL);
+ av_dict_set(metadata, name, ap, AV_DICT_DONT_STRDUP_VAL);
return 0;
}
-static int add_shorts_metadata(int count, const char *name,
- const char *sep, TiffContext *s, AVFrame *frame)
+int tiff_add_shorts_metadata(int count, const char *name,
+ const char *sep,
+ GetByteContext *gb, int le, AVDictionary
**metadata)
{
char *ap;
int i;
@@ -307,7 +308,7 @@ static int add_shorts_metadata(int count, const char *name,
if (count >= INT_MAX / sizeof(int16_t) || count <= 0)
return AVERROR_INVALIDDATA;
- if (bytestream2_get_bytes_left(&s->gb) < count * sizeof(int16_t))
+ if (bytestream2_get_bytes_left(gb) < count * sizeof(int16_t))
return AVERROR_INVALIDDATA;
sp = av_malloc(count * sizeof(int16_t));
@@ -315,41 +316,41 @@ static int add_shorts_metadata(int count, const char *name,
return AVERROR(ENOMEM);
for (i = 0; i < count; i++)
- sp[i] = tget_short(&s->gb, s->le);
+ sp[i] = tget_short(gb, le);
ap = shorts2str(sp, count, sep);
av_freep(&sp);
if (!ap)
return AVERROR(ENOMEM);
- av_dict_set(avpriv_frame_get_metadatap(frame), name, ap,
AV_DICT_DONT_STRDUP_VAL);
+ av_dict_set(metadata, name, ap, AV_DICT_DONT_STRDUP_VAL);
return 0;
}
-static int add_string_metadata(int count, const char *name,
- TiffContext *s, AVFrame *frame)
+int tiff_add_string_metadata(int count, const char *name,
+ GetByteContext *gb, int le, AVDictionary
**metadata)
{
char *value;
- if (bytestream2_get_bytes_left(&s->gb) < count || count < 0)
+ if (bytestream2_get_bytes_left(gb) < count || count < 0)
return AVERROR_INVALIDDATA;
value = av_malloc(count + 1);
if (!value)
return AVERROR(ENOMEM);
- bytestream2_get_bufferu(&s->gb, value, count);
+ bytestream2_get_bufferu(gb, value, count);
value[count] = 0;
- av_dict_set(avpriv_frame_get_metadatap(frame), name, value,
AV_DICT_DONT_STRDUP_VAL);
+ av_dict_set(metadata, name, value, AV_DICT_DONT_STRDUP_VAL);
return 0;
}
-static int add_metadata(int count, int type,
- const char *name, const char *sep, TiffContext *s,
AVFrame *frame)
+static int add_metadata(int count, int type, const char *name, const char *sep,
+ GetByteContext *gb, int le, AVDictionary **metadata)
{
switch(type) {
- case TIFF_DOUBLE: return add_doubles_metadata(count, name, sep, s, frame);
- case TIFF_SHORT : return add_shorts_metadata(count, name, sep, s, frame);
- case TIFF_STRING: return add_string_metadata(count, name, s, frame);
+ case TIFF_DOUBLE: return tiff_add_doubles_metadata(count, name, sep, gb,
le, metadata);
+ case TIFF_SHORT : return tiff_add_shorts_metadata(count, name, sep, gb, le,
metadata);
+ case TIFF_STRING: return tiff_add_string_metadata(count, name, gb, le,
metadata);
default : return AVERROR_INVALIDDATA;
};
}
@@ -694,6 +695,47 @@ static int init_image(TiffContext *s, AVFrame *frame)
return 0;
}
+int tiff_decode_header(GetByteContext *gb, int *le, int *ifd_offset)
+{
+ if (bytestream2_get_bytes_left(gb) < 8) {
+ return AVERROR_INVALIDDATA;
+ }
+
+ *le = bytestream2_get_le16u(gb);
+ if (*le == AV_RB16("II")) {
+ *le = 1;
+ } else if (*le == AV_RB16("MM")) {
+ *le = 0;
+ } else {
+ return AVERROR_INVALIDDATA;
+ }
+
+ if (tget_short(gb, *le) != 42) {
+ return AVERROR_INVALIDDATA;
+ }
+
+ *ifd_offset = tget_long(gb, *le);
+
+ return 0;
+}
+
+void tiff_read_tag_data(GetByteContext *gb, int le, unsigned *tag, unsigned
*type, unsigned *count, unsigned *offset)
+{
+ *tag = tget_short(gb, le);
+ *type = tget_short(gb, le);
+ *count = tget_long (gb, le);
+ *offset = tget_long (gb, le);
+}
+
+void tiff_seek_tag_value(GetByteContext *gb, unsigned type, unsigned count,
unsigned offset)
+{
+ if (count <= 4 && (type_sizes[type] * count <= 4 || type == TIFF_STRING)) {
+ bytestream2_seek(gb, -4, SEEK_CUR);
+ } else {
+ bytestream2_seek(gb, offset, SEEK_SET);
+ }
+}
+
static int tiff_decode_tag(TiffContext *s, AVFrame *frame)
{
unsigned tag, type, count, off, value = 0;
@@ -702,10 +744,7 @@ static int tiff_decode_tag(TiffContext *s, AVFrame *frame)
uint32_t *pal;
double *dp;
- tag = tget_short(&s->gb, s->le);
- type = tget_short(&s->gb, s->le);
- count = tget_long(&s->gb, s->le);
- off = tget_long(&s->gb, s->le);
+ tiff_read_tag_data(&s->gb, s->le, &tag, &type, &count, &off);
start = bytestream2_tell(&s->gb);
if (type == 0 || type >= FF_ARRAY_ELEMS(type_sizes)) {
@@ -714,30 +753,20 @@ static int tiff_decode_tag(TiffContext *s, AVFrame *frame)
return 0;
}
+ tiff_seek_tag_value(&s->gb, type, count, off);
if (count == 1) {
switch (type) {
case TIFF_BYTE:
case TIFF_SHORT:
- bytestream2_seek(&s->gb, -4, SEEK_CUR);
value = tget(&s->gb, type, s->le);
break;
case TIFF_LONG:
value = off;
break;
- case TIFF_STRING:
- if (count <= 4) {
- bytestream2_seek(&s->gb, -4, SEEK_CUR);
- break;
- }
default:
value = UINT_MAX;
bytestream2_seek(&s->gb, off, SEEK_SET);
}
- } else {
- if (count <= 4 && type_sizes[type] * count <= 4)
- bytestream2_seek(&s->gb, -4, SEEK_CUR);
- else
- bytestream2_seek(&s->gb, off, SEEK_SET);
}
switch (tag) {
@@ -927,7 +956,7 @@ static int tiff_decode_tag(TiffContext *s, AVFrame *frame)
s->fax_opts = value;
break;
#define ADD_METADATA(count, name, sep)\
- if ((ret = add_metadata(count, type, name, sep, s, frame)) < 0) {\
+ if ((ret = add_metadata(count, type, name, sep, &s->gb, s->le,
avpriv_frame_get_metadatap(frame))) < 0) {\
av_log(s->avctx, AV_LOG_ERROR, "Error allocating temporary buffer\n");\
return ret;\
}
@@ -1075,7 +1104,7 @@ static int decode_frame(AVCodecContext *avctx,
TiffContext *const s = avctx->priv_data;
AVFrame *const p = data;
unsigned off;
- int id, le, ret, plane, planes;
+ int le, ret, plane, planes;
int i, j, entries, stride;
unsigned soff, ssize;
uint8_t *dst;
@@ -1085,17 +1114,14 @@ static int decode_frame(AVCodecContext *avctx,
bytestream2_init(&s->gb, avpkt->data, avpkt->size);
// parse image header
- if (avpkt->size < 8)
- return AVERROR_INVALIDDATA;
- id = bytestream2_get_le16u(&s->gb);
- if (id == 0x4949)
- le = 1;
- else if (id == 0x4D4D)
- le = 0;
- else {
- av_log(avctx, AV_LOG_ERROR, "TIFF header not found\n");
+ if ((ret = tiff_decode_header(&s->gb, &le, &off))) {
+ av_log(avctx, AV_LOG_ERROR, "Invalid TIFF header\n");
+ return ret;
+ } else if (off >= UINT_MAX - 14 || avpkt->size < off + 14) {
+ av_log(avctx, AV_LOG_ERROR, "IFD offset is greater than image size\n");
return AVERROR_INVALIDDATA;
}
+
s->le = le;
// TIFF_BPP is not a required tag and defaults to 1
s->bppcount = s->bpp = 1;
@@ -1104,21 +1130,9 @@ static int decode_frame(AVCodecContext *avctx,
s->fill_order = 0;
free_geotags(s);
- // As TIFF 6.0 specification puts it "An arbitrary but carefully chosen number
- // that further identifies the file as a TIFF file"
- if (tget_short(&s->gb, le) != 42) {
- av_log(avctx, AV_LOG_ERROR,
- "The answer to life, universe and everything is not correct!\n");
- return AVERROR_INVALIDDATA;
- }
// Reset these offsets so we can tell if they were set this frame
s->stripsizesoff = s->strippos = 0;
/* parse image file directory */
- off = tget_long(&s->gb, le);
- if (off >= UINT_MAX - 14 || avpkt->size < off + 14) {
- av_log(avctx, AV_LOG_ERROR, "IFD offset is greater than image size\n");
- return AVERROR_INVALIDDATA;
- }
bytestream2_seek(&s->gb, off, SEEK_SET);
entries = tget_short(&s->gb, le);
if (bytestream2_get_bytes_left(&s->gb) < entries * 12)
diff --git a/libavcodec/tiff.h b/libavcodec/tiff.h
index 3ea2158..3274807 100644
--- a/libavcodec/tiff.h
+++ b/libavcodec/tiff.h
@@ -31,6 +31,7 @@
#define AVCODEC_TIFF_H
#include <stdint.h>
+#include "bytestream.h"
/** abridged list of TIFF tags */
enum TiffTags {
@@ -190,4 +191,18 @@ typedef struct TiffGeoTagNameType {
const enum TiffGeoTagType type;
} TiffGeoTagNameType;
+int tiff_decode_header(GetByteContext *gb, int *le, int *ifd_offset);
+void tiff_read_tag_data(GetByteContext *gb, int le, unsigned *tag, unsigned
*type, unsigned *count, unsigned *offset);
+void tiff_seek_tag_value(GetByteContext *gb, unsigned type, unsigned count,
unsigned offset);
+
+unsigned tget_short(GetByteContext *gb, int le);
+unsigned tget_long(GetByteContext *gb, int le);
+
+int tiff_add_doubles_metadata(int count, const char *name, const char *sep,
+ GetByteContext *gb, int le, AVDictionary **metadata);
+int tiff_add_shorts_metadata(int count, const char *name, const char *sep,
+ GetByteContext *gb, int le, AVDictionary **metadata);
+int tiff_add_string_metadata(int count, const char *name,
+ GetByteContext *gb, int le, AVDictionary **metadata);
+
#endif /* AVCODEC_TIFF_H */
--
1.7.4.3
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