Commit 49e1ff89 authored by Tim-Philipp Müller's avatar Tim-Philipp Müller 🐠
Browse files

gst/avi/gstavisubtitle.c: Detect other UTF byte order markers and convert to UTF-8 as appropriate.

Original commit message from CVS:
* gst/avi/gstavisubtitle.c: (IS_BOM_UTF8), (IS_BOM_UTF16_BE),
(IS_BOM_UTF16_LE), (IS_BOM_UTF32_BE), (IS_BOM_UTF32_LE),
(gst_avi_subtitle_extract_file), (gst_avi_subtitle_parse_gab2_chunk):
Detect other UTF byte order markers and convert to UTF-8 as
appropriate.
parent 87aed1a2
2007-12-18 Tim-Philipp Müller <tim at centricular dot net>
* gst/avi/gstavisubtitle.c: (IS_BOM_UTF8), (IS_BOM_UTF16_BE),
(IS_BOM_UTF16_LE), (IS_BOM_UTF32_BE), (IS_BOM_UTF32_LE),
(gst_avi_subtitle_extract_file), (gst_avi_subtitle_parse_gab2_chunk):
Detect other UTF byte order markers and convert to UTF-8 as
appropriate.
2007-12-18 Tim-Philipp Müller <tim at centricular dot net>
 
* gst/avi/gstavisubtitle.c: (src_template),
......
......@@ -18,7 +18,7 @@
* Boston, MA 02111-1307, USA.
*/
/* FIXME: BOM detection and format conversion; validate UTF-8; handle seeks */
/* FIXME: handle seeks, documentation */
/* example of a subtitle chunk in an avi file
* 00000000: 47 41 42 32 00 02 00 10 00 00 00 45 00 6e 00 67 GAB2.......E.n.g
......@@ -64,24 +64,72 @@ static GstStateChangeReturn gst_avi_subtitle_change_state (GstElement * element,
GST_BOILERPLATE (GstAviSubtitle, gst_avi_subtitle, GstElement,
GST_TYPE_ELEMENT);
#define IS_BOM_UTF8(data) ((GST_READ_UINT32_BE(data) >> 8) == 0xEFBBBF)
#define IS_BOM_UTF16_BE(data) (GST_READ_UINT16_BE(data) == 0xFEFF)
#define IS_BOM_UTF16_LE(data) (GST_READ_UINT16_LE(data) == 0xFEFF)
#define IS_BOM_UTF32_BE(data) (GST_READ_UINT32_BE(data) == 0xFEFF)
#define IS_BOM_UTF32_LE(data) (GST_READ_UINT32_LE(data) == 0xFEFF)
static GstBuffer *
gst_avi_subtitle_extract_utf8_file (GstBuffer * buffer, guint offset, guint len)
gst_avi_subtitle_extract_file (GstAviSubtitle * sub, GstBuffer * buffer,
guint offset, guint len)
{
guint8 *file = GST_BUFFER_DATA (buffer) + offset;
const gchar *input_enc = NULL;
GstBuffer *ret;
gchar *data;
data = (gchar *) GST_BUFFER_DATA (buffer) + offset;
if (len >= (3 + 1) && IS_BOM_UTF8 (data) &&
g_utf8_validate (data + 3, len - 3, NULL)) {
ret = gst_buffer_create_sub (buffer, offset + 3, len - 3);
} else if (len >= 2 && IS_BOM_UTF16_BE (data)) {
input_enc = "UTF-16BE";
data += 2;
len -= 2;
} else if (len >= 2 && IS_BOM_UTF16_LE (data)) {
input_enc = "UTF-16LE";
data += 2;
len -= 2;
} else if (len >= 4 && IS_BOM_UTF32_BE (data)) {
input_enc = "UTF-32BE";
data += 4;
len -= 4;
} else if (len >= 4 && IS_BOM_UTF32_LE (data)) {
input_enc = "UTF-32LE";
data += 4;
len -= 4;
} else if (g_utf8_validate (data, len, NULL)) {
/* not specified, check if it's UTF-8 */
ret = gst_buffer_create_sub (buffer, offset, len);
} else {
/* we could fall back to gst_tag_freeform_to_utf8() here */
GST_WARNING_OBJECT (sub, "unspecified encoding, and not UTF-8");
return NULL;
}
if (input_enc) {
GError *err = NULL;
gchar *utf8;
if (file[0] == 0xEF && file[1] == 0xBB && file[2] == 0xBF) {
/* UTF-8 */
return gst_buffer_create_sub (buffer, offset + 3, len - 3);
GST_DEBUG_OBJECT (sub, "converting subtitles from %s to UTF-8", input_enc);
utf8 = g_convert (data, len, "UTF-8", input_enc, NULL, NULL, &err);
if (err != NULL) {
GST_WARNING_OBJECT (sub, "conversion to UTF-8 failed : %s", err->message);
g_error_free (err);
return NULL;
}
ret = gst_buffer_new ();
GST_BUFFER_DATA (ret) = (guint8 *) utf8;
GST_BUFFER_MALLOCDATA (ret) = (guint8 *) utf8;
GST_BUFFER_SIZE (ret) = strlen (utf8);
GST_BUFFER_OFFSET (ret) = 0;
}
/* TODO Check for:
* 00 00 FE FF UTF-32, big-endian
* FF FE 00 00 UTF-32, little-endian
* FE FF UTF-16, big-endian
* FF FE UTF-16, little-endian
*/
/* No BOM detected assuming UTF-8 */
return gst_buffer_create_sub (buffer, offset, len);
GST_BUFFER_CAPS (ret) = gst_caps_new_simple ("application/x-subtitle", NULL);
return ret;
}
static GstFlowReturn
......@@ -129,7 +177,10 @@ gst_avi_subtitle_parse_gab2_chunk (GstAviSubtitle * sub, GstBuffer * buf)
* assume all the remaining data in the chunk is subtitle data, there may
* be padding at the end for some reason, so only parse file_length bytes */
sub->subfile =
gst_avi_subtitle_extract_utf8_file (buf, 17 + name_length, file_length);
gst_avi_subtitle_extract_file (sub, buf, 17 + name_length, file_length);
if (sub->subfile == NULL)
goto extract_failed;
return GST_FLOW_OK;
......@@ -159,6 +210,12 @@ wrong_total_length:
17 + name_length + file_length, size));
return GST_FLOW_ERROR;
}
extract_failed:
{
GST_ELEMENT_ERROR (sub, STREAM, DECODE, (NULL),
("could not extract subtitles"));
return GST_FLOW_ERROR;
}
}
static GstFlowReturn
......
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