gst-libs/gst/tag/: API: add gst_tag_image_data_to_image_buffer()

Original commit message from CVS:
* gst-libs/gst/tag/gstid3tag.c: (gst_tag_list_add_id3_image):
* gst-libs/gst/tag/tag.h: (GST_TAG_IMAGE_TYPE_NONE),
* gst-libs/gst/tag/tags.c: (register_tag_image_type_enum),
(gst_tag_image_type_get_type), (gst_tag_image_type_is_valid),
(gst_tag_image_data_to_image_buffer):
Add two utility functions to avoid code duplication ():
API: add gst_tag_image_data_to_image_buffer()
API: add gst_tag_list_add_id3_image()
This commit is contained in:
Tim-Philipp Müller 2008-06-03 19:29:06 +00:00
parent eb93e07392
commit cd9bb9a674
4 changed files with 203 additions and 2 deletions

View file

@ -1,3 +1,14 @@
2008-06-03 Tim-Philipp Müller <tim.muller at collabora co uk>
* gst-libs/gst/tag/gstid3tag.c: (gst_tag_list_add_id3_image):
* gst-libs/gst/tag/tag.h: (GST_TAG_IMAGE_TYPE_NONE),
* gst-libs/gst/tag/tags.c: (register_tag_image_type_enum),
(gst_tag_image_type_get_type), (gst_tag_image_type_is_valid),
(gst_tag_image_data_to_image_buffer):
Add two utility functions to avoid code duplication (#512333):
API: add gst_tag_image_data_to_image_buffer()
API: add gst_tag_list_add_id3_image()
2008-06-03 Sebastian Dröge <slomo@circular-chaos.org>
* win32/common/libgstaudio.def:

View file

@ -428,3 +428,58 @@ gst_tag_id3_genre_get (const guint id)
return NULL;
return genres[id];
}
/**
* gst_tag_list_add_id3_image:
* @tag_list: a tag list
* @image_data: the (encoded) image
* @image_data_len: the length of the encoded image data at @image_data
* @id3_picture_type: picture type as per the ID3 (v2.4.0) specification for
* the APIC frame (0 = unknown/other)
*
* Adds an image from an ID3 APIC frame (or similar, such as used in FLAC)
* to the given tag list. Also see gst_tag_image_data_to_image_buffer() for
* more information on image tags in GStreamer.
*
* Returns: %TRUE if the image was processed, otherwise %FALSE
*
* Since: 0.10.20
*/
gboolean
gst_tag_list_add_id3_image (GstTagList * tag_list, const guint8 * image_data,
guint image_data_len, guint id3_picture_type)
{
GstTagImageType tag_image_type;
const gchar *tag_name;
GstBuffer *image;
g_return_val_if_fail (GST_IS_TAG_LIST (tag_list), FALSE);
g_return_val_if_fail (image_data != NULL, FALSE);
g_return_val_if_fail (image_data_len > 0, FALSE);
if (id3_picture_type == 0x01 || id3_picture_type == 0x02) {
/* file icon for preview. Don't add image-type to caps, since there
* is only supposed to be one of these, and the type is already indicated
* via the special tag */
tag_name = GST_TAG_PREVIEW_IMAGE;
tag_image_type = GST_TAG_IMAGE_TYPE_NONE;
} else {
tag_name = GST_TAG_IMAGE;
/* Remap the ID3v2 APIC type our ImageType enum */
if (id3_picture_type >= 0x3 && id3_picture_type <= 0x14)
tag_image_type = (GstTagImageType) (id3_picture_type - 2);
else
tag_image_type = GST_TAG_IMAGE_TYPE_UNDEFINED;
}
image = gst_tag_image_data_to_image_buffer (image_data, image_data_len,
tag_image_type);
if (image == NULL)
return FALSE;
gst_tag_list_add (tag_list, GST_TAG_MERGE_APPEND, tag_name, image, NULL);
gst_buffer_unref (image);
return TRUE;
}

View file

@ -126,6 +126,9 @@ G_BEGIN_DECLS
/**
* GstTagImageType:
* @GST_TAG_IMAGE_TYPE_NONE : No image type. Can be used to
* tell functions such as gst_tag_image_data_to_image_buffer() that no
* image type should be set. (Since: 0.10.20)
* @GST_TAG_IMAGE_TYPE_UNDEFINED : Undefined/other image type
* @GST_TAG_IMAGE_TYPE_FRONT_COVER : Cover (front)
* @GST_TAG_IMAGE_TYPE_BACK_COVER : Cover (back)
@ -152,7 +155,8 @@ G_BEGIN_DECLS
* Since: 0.10.9
*/
typedef enum {
GST_TAG_IMAGE_TYPE_UNDEFINED,
GST_TAG_IMAGE_TYPE_NONE = -1,
GST_TAG_IMAGE_TYPE_UNDEFINED = 0,
GST_TAG_IMAGE_TYPE_FRONT_COVER,
GST_TAG_IMAGE_TYPE_BACK_COVER,
GST_TAG_IMAGE_TYPE_LEAFLET_PAGE,
@ -209,6 +213,11 @@ G_CONST_RETURN gchar * gst_tag_from_id3_user_tag (const gchar *
const gchar * id3_user_tag);
G_CONST_RETURN gchar * gst_tag_to_id3_tag (const gchar * gst_tag);
gboolean gst_tag_list_add_id3_image (GstTagList * tag_list,
const guint8 * image_data,
guint image_data_len,
guint id3_picture_type);
/* other tag-related functions */
gboolean gst_tag_parse_extended_comment (const gchar * ext_comment,
@ -221,6 +230,10 @@ gchar * gst_tag_freeform_string_to_utf8 (const gchar * data,
gint size,
const gchar ** env_vars);
GstBuffer * gst_tag_image_data_to_image_buffer (const guint8 * image_data,
guint image_data_len,
GstTagImageType image_type);
/* FIXME 0.11: replace with a more general gst_tag_library_init() */
void gst_tag_register_musicbrainz_tags (void);

View file

@ -1,6 +1,6 @@
/* GStreamer non-core tag registration and tag utility functions
* Copyright (C) 2005 Ross Burton <ross@burtonini.com>
* Copyright (C) 2006 Tim-Philipp Müller <tim centricular net>
* Copyright (C) 2006-2008 Tim-Philipp Müller <tim centricular net>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
@ -23,6 +23,7 @@
#endif
#include <gst/gst-i18n-plugin.h>
#include <gst/base/gsttypefindhelper.h>
#include <gst/gst.h>
#include "tag.h"
@ -144,6 +145,9 @@ register_tag_image_type_enum (GType * id)
};
*id = g_enum_register_static ("GstTagImageType", image_types);
/* work around thread-safety issue with class creation in GLib */
g_type_class_ref (*id);
}
GType
@ -156,6 +160,19 @@ gst_tag_image_type_get_type (void)
return id;
}
static inline gboolean
gst_tag_image_type_is_valid (GstTagImageType type)
{
GEnumClass *klass;
gboolean res;
klass = g_type_class_ref (gst_tag_image_type_get_type ());
res = (g_enum_get_value (klass, type) != NULL);
g_type_class_unref (klass);
return res;
}
/**
* gst_tag_parse_extended_comment:
* @ext_comment: an extended comment string, see #GST_TAG_EXTENDED_COMMENT
@ -326,3 +343,108 @@ beach:
g_free (utf8);
return NULL;
}
/**
* gst_tag_image_data_to_image_buffer:
* @image_data: the (encoded) image
* @image_data_len: the length of the encoded image data at @image_data
* @image_type: type of the image, or #GST_TAG_IMAGE_TYPE_UNDEFINED. Pass
* #GST_TAG_IMAGE_TYPE_NONE if no image type should be set at all (e.g.
* for preview images)
*
* Helper function for tag-reading plugins to create a #GstBuffer suitable to
* add to a #GstTagList as an image tag (such as #GST_TAG_IMAGE or
* #GST_TAG_PREVIEW_IMAGE) from the encoded image data and an (optional) image
* type.
*
* Background: cover art and other images in tags are usually stored as a
* blob of binary image data, often accompanied by a MIME type or some other
* content type string (e.g. 'png', 'jpeg', 'jpg'). Sometimes there is also an
* 'image type' to indicate what kind of image this is (e.g. front cover,
* back cover, artist, etc.). The image data may also be an URI to the image
* rather than the image itself.
*
* In GStreamer, image tags are #GstBuffer<!-- -->s containing the raw image
* data, with the buffer caps describing the content type of the image
* (e.g. image/jpeg, image/png, text/uri-list). The buffer caps may contain
* an additional 'image-type' field of #GST_TYPE_TAG_IMAGE_TYPE to describe
* the type of image (front cover, back cover etc.). #GST_TAG_PREVIEW_IMAGE
* tags should not carry an image type, their type is already indicated via
* the special tag name.
*
* This function will do various checks and typefind the encoded image
* data (we can't trust the declared mime type).
*
* Returns: a newly-allocated image buffer for use in tag lists, or NULL
*
* Since: 0.10.20
*/
GstBuffer *
gst_tag_image_data_to_image_buffer (const guint8 * image_data,
guint image_data_len, GstTagImageType image_type)
{
const gchar *name;
GstBuffer *image;
GstCaps *caps;
g_return_val_if_fail (image_data != NULL, NULL);
g_return_val_if_fail (image_data_len > 0, NULL);
g_return_val_if_fail (gst_tag_image_type_is_valid (image_type), NULL);
GST_DEBUG ("image data len: %u bytes", image_data_len);
/* allocate space for a NUL terminator for an uri too */
image = gst_buffer_try_new_and_alloc (image_data_len + 1);
if (image == NULL) {
GST_WARNING ("failed to allocate buffer of %d for image", image_data_len);
return NULL;
}
memcpy (GST_BUFFER_DATA (image), image_data, image_data_len);
GST_BUFFER_DATA (image)[image_data_len] = '\0';
GST_BUFFER_SIZE (image) = image_data_len;
/* Find GStreamer media type, can't trust declared type */
caps = gst_type_find_helper_for_buffer (NULL, image, NULL);
if (caps == NULL)
goto no_type;
GST_DEBUG ("Found GStreamer media type: %" GST_PTR_FORMAT, caps);
/* sanity check: make sure typefound/declared caps are either URI or image */
name = gst_structure_get_name (gst_caps_get_structure (caps, 0));
if (!g_str_has_prefix (name, "image/") &&
!g_str_has_prefix (name, "video/") &&
!g_str_equal (name, "text/uri-list")) {
GST_DEBUG ("Unexpected image type '%s', ignoring image frame", name);
goto error;
}
if (image_type != GST_TAG_IMAGE_TYPE_NONE) {
GST_LOG ("Setting image type: %d", image_type);
caps = gst_caps_make_writable (caps);
gst_caps_set_simple (caps, "image-type", GST_TYPE_TAG_IMAGE_TYPE,
image_type, NULL);
}
gst_buffer_set_caps (image, caps);
gst_caps_unref (caps);
return image;
/* ERRORS */
no_type:
{
GST_DEBUG ("Could not determine GStreamer media type, ignoring image");
/* fall through */
}
error:
{
if (image)
gst_buffer_unref (image);
if (caps)
gst_caps_unref (caps);
return NULL;
}
}