gstreamer/gst/id3demux/gstid3demux.c
2019-05-13 10:24:40 -04:00

289 lines
8.8 KiB
C

/* -*- Mode: C; tab-width: 2; indent-tabs-mode: t; c-basic-offset: 2 -*- */
/* GStreamer ID3 tag demuxer
* Copyright (C) 2005 Jan Schmidt <thaytan@mad.scientist.com>
* Copyright (C) 2003-2004 Benjamin Otte <otte@gnome.org>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
/**
* SECTION:element-id3demux
* @title: id3demux
*
* id3demux accepts data streams with either (or both) ID3v2 regions at the
* start, or ID3v1 at the end. The mime type of the data between the tag blocks
* is detected using typefind functions, and the appropriate output mime type
* set on outgoing buffers.
*
* The element is only able to read ID3v1 tags from a seekable stream, because
* they are at the end of the stream. That is, when get_range mode is supported
* by the upstream elements. If get_range operation is available, id3demux makes
* it available downstream. This means that elements which require get_range
* mode, such as wavparse, can operate on files containing ID3 tag information.
*
* This id3demux element replaced an older element with the same name which
* relied on libid3tag from the MAD project.
*
* ## Example launch line
* |[
* gst-launch-1.0 filesrc location=file.mp3 ! id3demux ! fakesink -t
* ]| This pipeline should read any available ID3 tag information and output it.
* The contents of the file inside the ID3 tag regions should be detected, and
* the appropriate mime type set on buffers produced from id3demux.
*
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gst/gst.h>
#include <gst/gst-i18n-plugin.h>
#include <gst/tag/tag.h>
#include <gst/pbutils/pbutils.h>
#include <string.h>
#include "gstid3demux.h"
enum
{
PROP_0,
PROP_PREFER_V1
};
#define DEFAULT_PREFER_V1 FALSE
GST_DEBUG_CATEGORY (id3demux_debug);
#define GST_CAT_DEFAULT (id3demux_debug)
#define ID3V1_TAG_SIZE 128
#define ID3V2_HDR_SIZE GST_TAG_ID3V2_HEADER_SIZE
static GstStaticPadTemplate sink_factory = GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("application/x-id3")
);
static gboolean gst_id3demux_identify_tag (GstTagDemux * demux,
GstBuffer * buffer, gboolean start_tag, guint * tag_size);
static GstTagDemuxResult gst_id3demux_parse_tag (GstTagDemux * demux,
GstBuffer * buffer, gboolean start_tag, guint * tag_size,
GstTagList ** tags);
static GstTagList *gst_id3demux_merge_tags (GstTagDemux * tagdemux,
const GstTagList * start_tags, const GstTagList * end_tags);
static void gst_id3demux_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec);
static void gst_id3demux_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec);
#define gst_id3demux_parent_class parent_class
G_DEFINE_TYPE (GstID3Demux, gst_id3demux, GST_TYPE_TAG_DEMUX);
static void
gst_id3demux_class_init (GstID3DemuxClass * klass)
{
GObjectClass *gobject_class = (GObjectClass *) klass;
GstElementClass *gstelement_class = (GstElementClass *) klass;
GstTagDemuxClass *tagdemux_class = (GstTagDemuxClass *) klass;
gobject_class->set_property = gst_id3demux_set_property;
gobject_class->get_property = gst_id3demux_get_property;
g_object_class_install_property (gobject_class, PROP_PREFER_V1,
g_param_spec_boolean ("prefer-v1", "Prefer version 1 tag",
"Prefer tags from ID3v1 tag at end of file when both ID3v1 "
"and ID3v2 tags are present", DEFAULT_PREFER_V1,
G_PARAM_READWRITE | G_PARAM_CONSTRUCT | G_PARAM_STATIC_STRINGS));
gst_element_class_add_static_pad_template (gstelement_class, &sink_factory);
gst_element_class_set_static_metadata (gstelement_class, "ID3 tag demuxer",
"Codec/Demuxer/Metadata",
"Read and output ID3v1 and ID3v2 tags while demuxing the contents",
"Jan Schmidt <thaytan@mad.scientist.com>");
tagdemux_class->identify_tag = GST_DEBUG_FUNCPTR (gst_id3demux_identify_tag);
tagdemux_class->parse_tag = GST_DEBUG_FUNCPTR (gst_id3demux_parse_tag);
tagdemux_class->merge_tags = GST_DEBUG_FUNCPTR (gst_id3demux_merge_tags);
tagdemux_class->min_start_size = ID3V2_HDR_SIZE;
tagdemux_class->min_end_size = ID3V1_TAG_SIZE;
}
static void
gst_id3demux_init (GstID3Demux * id3demux)
{
id3demux->prefer_v1 = DEFAULT_PREFER_V1;
}
static gboolean
gst_id3demux_identify_tag (GstTagDemux * demux, GstBuffer * buf,
gboolean start_tag, guint * tag_size)
{
guint8 data[3];
gst_buffer_extract (buf, 0, data, 3);
if (start_tag) {
if (data[0] != 'I' || data[1] != 'D' || data[2] != '3')
goto no_marker;
*tag_size = gst_tag_get_id3v2_tag_size (buf);
} else {
if (data[0] != 'T' || data[1] != 'A' || data[2] != 'G')
goto no_marker;
*tag_size = ID3V1_TAG_SIZE;
}
GST_INFO_OBJECT (demux, "Found ID3v%u marker, tag_size = %u",
(start_tag) ? 2 : 1, *tag_size);
return TRUE;
no_marker:
{
GST_DEBUG_OBJECT (demux, "No ID3v%u marker found", (start_tag) ? 2 : 1);
return FALSE;
}
}
static void
gst_id3demux_add_container_format (GstTagList * tags)
{
GstCaps *sink_caps;
sink_caps = gst_static_pad_template_get_caps (&sink_factory);
gst_pb_utils_add_codec_description_to_tag_list (tags,
GST_TAG_CONTAINER_FORMAT, sink_caps);
gst_caps_unref (sink_caps);
}
static GstTagDemuxResult
gst_id3demux_parse_tag (GstTagDemux * demux, GstBuffer * buffer,
gboolean start_tag, guint * tag_size, GstTagList ** tags)
{
if (start_tag) {
*tag_size = gst_tag_get_id3v2_tag_size (buffer);
*tags = gst_tag_list_from_id3v2_tag (buffer);
if (G_LIKELY (*tags != NULL)) {
gst_id3demux_add_container_format (*tags);
return GST_TAG_DEMUX_RESULT_OK;
} else {
return GST_TAG_DEMUX_RESULT_BROKEN_TAG;
}
} else {
GstMapInfo map;
gst_buffer_map (buffer, &map, GST_MAP_READ);
*tags = gst_tag_list_new_from_id3v1 (map.data);
gst_buffer_unmap (buffer, &map);
if (G_UNLIKELY (*tags == NULL))
return GST_TAG_DEMUX_RESULT_BROKEN_TAG;
gst_id3demux_add_container_format (*tags);
*tag_size = ID3V1_TAG_SIZE;
return GST_TAG_DEMUX_RESULT_OK;
}
}
static GstTagList *
gst_id3demux_merge_tags (GstTagDemux * tagdemux, const GstTagList * start_tags,
const GstTagList * end_tags)
{
GstID3Demux *id3demux;
GstTagList *merged;
gboolean prefer_v1;
id3demux = GST_ID3DEMUX (tagdemux);
GST_OBJECT_LOCK (id3demux);
prefer_v1 = id3demux->prefer_v1;
GST_OBJECT_UNLOCK (id3demux);
/* we merge in REPLACE mode, so put the less important tags first */
if (prefer_v1)
merged = gst_tag_list_merge (start_tags, end_tags, GST_TAG_MERGE_REPLACE);
else
merged = gst_tag_list_merge (end_tags, start_tags, GST_TAG_MERGE_REPLACE);
GST_LOG_OBJECT (id3demux, "start tags: %" GST_PTR_FORMAT, start_tags);
GST_LOG_OBJECT (id3demux, "end tags: %" GST_PTR_FORMAT, end_tags);
GST_LOG_OBJECT (id3demux, "merged tags: %" GST_PTR_FORMAT, merged);
return merged;
}
static void
gst_id3demux_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstID3Demux *id3demux;
id3demux = GST_ID3DEMUX (object);
switch (prop_id) {
case PROP_PREFER_V1:{
GST_OBJECT_LOCK (id3demux);
id3demux->prefer_v1 = g_value_get_boolean (value);
GST_OBJECT_UNLOCK (id3demux);
break;
}
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_id3demux_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec)
{
GstID3Demux *id3demux;
id3demux = GST_ID3DEMUX (object);
switch (prop_id) {
case PROP_PREFER_V1:
GST_OBJECT_LOCK (id3demux);
g_value_set_boolean (value, id3demux->prefer_v1);
GST_OBJECT_UNLOCK (id3demux);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static gboolean
plugin_init (GstPlugin * plugin)
{
GST_DEBUG_CATEGORY_INIT (id3demux_debug, "id3demux", 0,
"GStreamer ID3 tag demuxer");
gst_tag_register_musicbrainz_tags ();
return gst_element_register (plugin, "id3demux",
GST_RANK_PRIMARY, GST_TYPE_ID3DEMUX);
}
GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
GST_VERSION_MINOR,
id3demux,
"Demux ID3v1 and ID3v2 tags from a file",
plugin_init, VERSION, GST_LICENSE, GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN)