From 4a42d3b0ceab6ab04067b2051da46b9c02060d29 Mon Sep 17 00:00:00 2001 From: Thiago Santos Date: Mon, 9 Aug 2010 17:25:07 -0300 Subject: [PATCH] tags: exif: Fix inner tags offset rewriting Fixes a bug that made exif helper lib fail to rewrite inner ifd tags offsets when there were more than 1 inner ifd. --- gst-libs/gst/tag/gstexiftag.c | 91 ++++++++++++++++++++++++++++--------------- 1 file changed, 60 insertions(+), 31 deletions(-) diff --git a/gst-libs/gst/tag/gstexiftag.c b/gst-libs/gst/tag/gstexiftag.c index 94713af..ab28c1b 100644 --- a/gst-libs/gst/tag/gstexiftag.c +++ b/gst-libs/gst/tag/gstexiftag.c @@ -511,26 +511,46 @@ tagdata_copy (GstExifTagData * to, const GstExifTagData * from) } static void -gst_exif_tag_rewrite_offsets (GstExifWriter * writer, guint32 base_offset) +gst_exif_tag_rewrite_offsets (GstByteWriter * writer, gint byte_order, + guint32 offset, gint num_tags, GstByteWriter * inner_ifds_data) { - guint32 offset; + GstByteReader *reader; + gint i; + guint16 aux = -1; GST_LOG ("Rewriting tag entries offsets"); - offset = gst_byte_writer_get_size (&writer->tagwriter); - while (gst_byte_writer_get_pos (&writer->tagwriter) < - gst_byte_writer_get_size (&writer->tagwriter)) { + reader = (GstByteReader *) writer; + + if (num_tags == -1) { + if (byte_order == G_LITTLE_ENDIAN) { + gst_byte_reader_get_uint16_le (reader, &aux); + } else { + gst_byte_reader_get_uint16_be (reader, &aux); + } + if (aux == -1) { + GST_WARNING ("Failed to read number of tags, won't rewrite offsets"); + return; + } + num_tags = (gint) aux; + } + + g_return_if_fail (num_tags != -1); + + GST_DEBUG ("number of tags %d", num_tags); + + for (i = 0; i < num_tags; i++) { guint16 type = 0; guint32 cur_offset = 0; - GstByteReader *reader; gint byte_size = 0; guint32 count = 0; guint16 tag_id = 0; - reader = (GstByteReader *) & writer->tagwriter; + g_assert (gst_byte_writer_get_pos (writer) < + gst_byte_writer_get_size (writer)); /* read the type */ - if (writer->byte_order == G_LITTLE_ENDIAN) { + if (byte_order == G_LITTLE_ENDIAN) { if (!gst_byte_reader_get_uint16_le (reader, &tag_id)) break; if (!gst_byte_reader_get_uint16_le (reader, &type)) @@ -546,6 +566,8 @@ gst_exif_tag_rewrite_offsets (GstExifWriter * writer, guint32 base_offset) break; } + GST_LOG ("Parsed tag %x of type %u and count %u", tag_id, type, count); + switch (type) { case EXIF_TYPE_BYTE: case EXIF_TYPE_ASCII: @@ -570,25 +592,36 @@ gst_exif_tag_rewrite_offsets (GstExifWriter * writer, guint32 base_offset) /* adjust the offset if needed */ if (byte_size > 4 || tag_id == EXIF_GPS_IFD_TAG || tag_id == EXIF_IFD_TAG) { - if (writer->byte_order == G_LITTLE_ENDIAN) { + if (byte_order == G_LITTLE_ENDIAN) { if (gst_byte_reader_peek_uint32_le (reader, &cur_offset)) { - gst_byte_writer_put_uint32_le (&writer->tagwriter, - cur_offset + offset + base_offset); + gst_byte_writer_put_uint32_le (writer, cur_offset + offset); } } else { if (gst_byte_reader_peek_uint32_be (reader, &cur_offset)) { - gst_byte_writer_put_uint32_be (&writer->tagwriter, - cur_offset + offset + base_offset); + gst_byte_writer_put_uint32_be (writer, cur_offset + offset); } } - GST_DEBUG ("Rewriting tag offset from %u to (%u + %u + %u) %u", - cur_offset, cur_offset, offset, base_offset, - cur_offset + offset + base_offset); + GST_DEBUG ("Rewriting tag offset from %u to (%u + %u) %u", + cur_offset, cur_offset, offset, cur_offset + offset); + + if ((tag_id == EXIF_GPS_IFD_TAG || tag_id == EXIF_IFD_TAG) && + inner_ifds_data != NULL) { + /* needs special handling */ + if (!gst_byte_writer_set_pos (inner_ifds_data, cur_offset)) { + GST_WARNING ("Failed to position writer to rewrite inner ifd " + "offsets"); + continue; + } + + gst_exif_tag_rewrite_offsets (inner_ifds_data, byte_order, offset, -1, + NULL); + } } else { gst_byte_reader_skip (reader, 4); GST_DEBUG ("No need to rewrite tag offset"); } } + GST_LOG ("Done rewriting offsets"); } static void @@ -738,17 +771,9 @@ write_exif_ifd (const GstTagList * taglist, gboolean byte_order, } if (inner_tag_map) { - /* The base offset for this inner ifd is the sum of: - * - the current base offset - * - the total tag data of current this ifd - * - the total data of the current ifd - * - its own tag entry length still to be writen (12) - * - 4 bytes for the next ifd entry still to be writen - */ - inner_ifd = write_exif_ifd (taglist, byte_order, base_offset + - gst_byte_writer_get_size (&writer.tagwriter) + - gst_byte_writer_get_size (&writer.datawriter) + 12 + 4, - inner_tag_map); + /* base offset and tagheader size are added when rewriting offset */ + inner_ifd = write_exif_ifd (taglist, byte_order, + gst_byte_writer_get_size (&writer.datawriter), inner_tag_map); } if (inner_ifd) { @@ -782,8 +807,12 @@ write_exif_ifd (const GstTagList * taglist, gboolean byte_order, else gst_byte_writer_put_uint16_be (&writer.tagwriter, writer.tags_total); + GST_DEBUG ("Number of tags rewriten to %d", writer.tags_total); + /* now that we know the tag headers size, we can add the offsets */ - gst_exif_tag_rewrite_offsets (&writer, base_offset); + gst_exif_tag_rewrite_offsets (&writer.tagwriter, writer.byte_order, + base_offset + gst_byte_writer_get_size (&writer.tagwriter), + writer.tags_total, &writer.datawriter); return gst_exif_writer_reset_and_get_buffer (&writer); } @@ -853,9 +882,9 @@ parse_exif_ifd (GstExifReader * exif_reader, gint buf_offset, if (!parse_exif_tag_header (&reader, exif_reader->byte_order, &tagdata)) goto read_error; - GST_DEBUG ("Parsed tag: id 0x%x, type %u, count %u, offset %u (0x%x)", - tagdata.tag, tagdata.tag_type, tagdata.count, tagdata.offset, - tagdata.offset); + GST_DEBUG ("Parsed tag: id 0x%x, type %u, count %u, offset %u (0x%x)" + ", buf size: %u", tagdata.tag, tagdata.tag_type, tagdata.count, + tagdata.offset, tagdata.offset, gst_byte_reader_get_size (&reader)); map_index = exif_tag_map_find_reverse (tagdata.tag, tag_map, TRUE); if (map_index == -1) { -- 2.7.4