blob: e2e239f4a5c8527b35c5d0fefc10c8af8cbe73b3 [file] [log] [blame]
/* GStreamer
* Copyright (C) 2003 Christophe Fergeau <teuf@gnome.org>
* Copyright (C) 2008 Jonathan Matthew <jonathan@d14n.org>
* Copyright (C) 2008 Sebastian Dröge <sebastian.droege@collabora.co.uk>
*
* gstflactag.c: plug-in for reading/modifying vorbis comments in flac files
*
* 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-flactag
* @see_also: #flacenc, #flacdec, #GstTagSetter
*
* The flactag element can change the tag contained within a raw
* FLAC stream. Specifically, it modifies the comments header packet
* of the FLAC stream.
*
* Applications can set the tags to write using the #GstTagSetter interface.
* Tags contained withing the FLAC bitstream will be picked up
* automatically (and merged according to the merge mode set via the tag
* setter interface).
*
* <refsect2>
* <title>Example pipelines</title>
* |[
* gst-launch-1.0 -v filesrc location=foo.flac ! flactag ! filesink location=bar.flac
* ]| This element is not useful with gst-launch, because it does not support
* setting the tags on a #GstTagSetter interface. Conceptually, the element
* will usually be used in this order though.
* </refsect2>
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gst/gst.h>
#include <gst/gsttagsetter.h>
#include <gst/base/gstadapter.h>
#include <gst/tag/tag.h>
#include <string.h>
#include "gstflactag.h"
GST_DEBUG_CATEGORY_STATIC (flactag_debug);
#define GST_CAT_DEFAULT flactag_debug
/* elementfactory information */
static GstStaticPadTemplate flac_tag_src_template =
GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("audio/x-flac")
);
static GstStaticPadTemplate flac_tag_sink_template =
GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("audio/x-flac")
);
static void gst_flac_tag_dispose (GObject * object);
static GstFlowReturn gst_flac_tag_chain (GstPad * pad, GstObject * parent,
GstBuffer * buffer);
static GstStateChangeReturn gst_flac_tag_change_state (GstElement * element,
GstStateChange transition);
static gboolean gst_flac_tag_sink_event (GstPad * pad, GstObject * parent,
GstEvent * event);
#define gst_flac_tag_parent_class parent_class
G_DEFINE_TYPE_WITH_CODE (GstFlacTag, gst_flac_tag, GST_TYPE_ELEMENT,
G_IMPLEMENT_INTERFACE (GST_TYPE_TAG_SETTER, NULL));
static void
gst_flac_tag_class_init (GstFlacTagClass * klass)
{
GstElementClass *gstelement_class;
GObjectClass *gobject_class;
GST_DEBUG_CATEGORY_INIT (flactag_debug, "flactag", 0, "flac tag rewriter");
gstelement_class = (GstElementClass *) klass;
gobject_class = (GObjectClass *) klass;
gobject_class->dispose = gst_flac_tag_dispose;
gstelement_class->change_state = gst_flac_tag_change_state;
gst_element_class_set_static_metadata (gstelement_class, "FLAC tagger",
"Formatter/Metadata",
"Rewrite tags in a FLAC file", "Christophe Fergeau <teuf@gnome.org>");
gst_element_class_add_static_pad_template (gstelement_class,
&flac_tag_sink_template);
gst_element_class_add_static_pad_template (gstelement_class,
&flac_tag_src_template);
}
static void
gst_flac_tag_dispose (GObject * object)
{
GstFlacTag *tag = GST_FLAC_TAG (object);
if (tag->adapter) {
g_object_unref (tag->adapter);
tag->adapter = NULL;
}
if (tag->vorbiscomment) {
gst_buffer_unref (tag->vorbiscomment);
tag->vorbiscomment = NULL;
}
if (tag->tags) {
gst_tag_list_unref (tag->tags);
tag->tags = NULL;
}
G_OBJECT_CLASS (parent_class)->dispose (object);
}
static void
gst_flac_tag_init (GstFlacTag * tag)
{
/* create the sink and src pads */
tag->sinkpad =
gst_pad_new_from_static_template (&flac_tag_sink_template, "sink");
gst_pad_set_chain_function (tag->sinkpad,
GST_DEBUG_FUNCPTR (gst_flac_tag_chain));
gst_pad_set_event_function (tag->sinkpad,
GST_DEBUG_FUNCPTR (gst_flac_tag_sink_event));
gst_element_add_pad (GST_ELEMENT (tag), tag->sinkpad);
tag->srcpad =
gst_pad_new_from_static_template (&flac_tag_src_template, "src");
gst_element_add_pad (GST_ELEMENT (tag), tag->srcpad);
tag->adapter = gst_adapter_new ();
}
static gboolean
gst_flac_tag_sink_event (GstPad * pad, GstObject * parent, GstEvent * event)
{
GstFlacTag *tag;
gboolean ret;
tag = GST_FLAC_TAG (parent);
GST_DEBUG_OBJECT (pad, "Received %s event on sinkpad, %" GST_PTR_FORMAT,
GST_EVENT_TYPE_NAME (event), event);
switch (GST_EVENT_TYPE (event)) {
case GST_EVENT_CAPS:
/* FIXME: parse and store the caps. Once we parsed and built the headers,
* update the "streamheader" field in the caps and send a new caps event
*/
ret = gst_pad_push_event (tag->srcpad, event);
break;
default:
ret = gst_pad_event_default (pad, parent, event);
break;
}
return ret;
}
#define FLAC_MAGIC "fLaC"
#define FLAC_MAGIC_SIZE (sizeof (FLAC_MAGIC) - 1)
static GstFlowReturn
gst_flac_tag_chain (GstPad * pad, GstObject * parent, GstBuffer * buffer)
{
GstFlacTag *tag;
GstFlowReturn ret;
GstMapInfo map;
gsize size;
ret = GST_FLOW_OK;
tag = GST_FLAC_TAG (parent);
gst_adapter_push (tag->adapter, buffer);
GST_LOG_OBJECT (pad, "state: %d", tag->state);
/* Initial state, we don't even know if we are dealing with a flac file */
if (tag->state == GST_FLAC_TAG_STATE_INIT) {
GstBuffer *id_buffer;
if (gst_adapter_available (tag->adapter) < sizeof (FLAC_MAGIC))
goto cleanup;
id_buffer = gst_adapter_take_buffer (tag->adapter, FLAC_MAGIC_SIZE);
GST_DEBUG_OBJECT (tag, "looking for " FLAC_MAGIC " identifier");
if (gst_buffer_memcmp (id_buffer, 0, FLAC_MAGIC, FLAC_MAGIC_SIZE) == 0) {
GST_DEBUG_OBJECT (tag, "pushing " FLAC_MAGIC " identifier buffer");
ret = gst_pad_push (tag->srcpad, id_buffer);
if (ret != GST_FLOW_OK)
goto cleanup;
tag->state = GST_FLAC_TAG_STATE_METADATA_BLOCKS;
} else {
/* FIXME: does that work well with FLAC files containing ID3v2 tags ? */
gst_buffer_unref (id_buffer);
GST_ELEMENT_ERROR (tag, STREAM, WRONG_TYPE, (NULL), (NULL));
ret = GST_FLOW_ERROR;
}
}
/* The fLaC magic string has been skipped, try to detect the beginning
* of a metadata block
*/
if (tag->state == GST_FLAC_TAG_STATE_METADATA_BLOCKS) {
guint type;
gboolean is_last;
const guint8 *block_header;
g_assert (tag->metadata_block_size == 0);
g_assert (tag->metadata_last_block == FALSE);
/* The header of a flac metadata block is 4 bytes long:
* 1st bit: indicates whether this is the last metadata info block
* 7 next bits: 4 if vorbis comment block
* 24 next bits: size of the metadata to follow (big endian)
*/
if (gst_adapter_available (tag->adapter) < 4)
goto cleanup;
block_header = gst_adapter_map (tag->adapter, 4);
is_last = ((block_header[0] & 0x80) == 0x80);
type = block_header[0] & 0x7F;
size = (block_header[1] << 16)
| (block_header[2] << 8)
| block_header[3];
gst_adapter_unmap (tag->adapter);
/* The 4 bytes long header isn't included in the metadata size */
tag->metadata_block_size = size + 4;
tag->metadata_last_block = is_last;
GST_DEBUG_OBJECT (tag,
"got metadata block: %" G_GSIZE_FORMAT " bytes, type %d, "
"is vorbiscomment: %d, is last: %d",
size, type, (type == 0x04), is_last);
/* Metadata blocks of type 4 are vorbis comment blocks */
if (type == 0x04) {
tag->state = GST_FLAC_TAG_STATE_VC_METADATA_BLOCK;
} else {
tag->state = GST_FLAC_TAG_STATE_WRITING_METADATA_BLOCK;
}
}
/* Reads a metadata block */
if ((tag->state == GST_FLAC_TAG_STATE_WRITING_METADATA_BLOCK) ||
(tag->state == GST_FLAC_TAG_STATE_VC_METADATA_BLOCK)) {
GstBuffer *metadata_buffer;
if (gst_adapter_available (tag->adapter) < tag->metadata_block_size)
goto cleanup;
metadata_buffer = gst_adapter_take_buffer (tag->adapter,
tag->metadata_block_size);
/* clear the is-last flag, as the last metadata block will
* be the vorbis comment block which we will build ourselves.
*/
gst_buffer_map (metadata_buffer, &map, GST_MAP_READWRITE);
map.data[0] &= (~0x80);
gst_buffer_unmap (metadata_buffer, &map);
if (tag->state == GST_FLAC_TAG_STATE_WRITING_METADATA_BLOCK) {
GST_DEBUG_OBJECT (tag, "pushing metadata block buffer");
ret = gst_pad_push (tag->srcpad, metadata_buffer);
if (ret != GST_FLOW_OK)
goto cleanup;
} else {
tag->vorbiscomment = metadata_buffer;
}
tag->metadata_block_size = 0;
tag->state = GST_FLAC_TAG_STATE_METADATA_NEXT_BLOCK;
}
/* This state is mainly used to be able to stop as soon as we read
* a vorbiscomment block from the flac file if we are in an only output
* tags mode
*/
if (tag->state == GST_FLAC_TAG_STATE_METADATA_NEXT_BLOCK) {
/* Check if in the previous iteration we read a vorbis comment metadata
* block, and stop now if the user only wants to read tags
*/
if (tag->vorbiscomment != NULL) {
guint8 id_data[4];
/* We found some tags, try to parse them and notify the other elements
* that we encountered some tags
*/
GST_DEBUG_OBJECT (tag, "emitting vorbiscomment tags");
gst_buffer_extract (tag->vorbiscomment, 0, id_data, 4);
tag->tags = gst_tag_list_from_vorbiscomment_buffer (tag->vorbiscomment,
id_data, 4, NULL);
if (tag->tags != NULL) {
gst_pad_push_event (tag->srcpad,
gst_event_new_tag (gst_tag_list_ref (tag->tags)));
}
gst_buffer_unref (tag->vorbiscomment);
tag->vorbiscomment = NULL;
}
/* Skip to next state */
if (tag->metadata_last_block == FALSE) {
tag->state = GST_FLAC_TAG_STATE_METADATA_BLOCKS;
} else {
tag->state = GST_FLAC_TAG_STATE_ADD_VORBIS_COMMENT;
}
}
/* Creates a vorbis comment block from the metadata which was set
* on the gstreamer element, and add it to the flac stream
*/
if (tag->state == GST_FLAC_TAG_STATE_ADD_VORBIS_COMMENT) {
GstBuffer *buffer;
const GstTagList *user_tags;
GstTagList *merged_tags;
/* merge the tag lists */
user_tags = gst_tag_setter_get_tag_list (GST_TAG_SETTER (tag));
if (user_tags != NULL) {
merged_tags = gst_tag_list_merge (user_tags, tag->tags,
gst_tag_setter_get_tag_merge_mode (GST_TAG_SETTER (tag)));
} else {
merged_tags = gst_tag_list_copy (tag->tags);
}
if (merged_tags == NULL) {
/* If we get a NULL list of tags, we must generate a padding block
* which is marked as the last metadata block, otherwise we'll
* end up with a corrupted flac file.
*/
GST_WARNING_OBJECT (tag, "No tags found");
buffer = gst_buffer_new_and_alloc (12);
if (buffer == NULL)
goto no_buffer;
gst_buffer_map (buffer, &map, GST_MAP_WRITE);
memset (map.data, 0, map.size);
map.data[0] = 0x81; /* 0x80 = Last metadata block,
* 0x01 = padding block */
gst_buffer_unmap (buffer, &map);
} else {
guchar header[4];
guint8 fbit[1];
memset (header, 0, sizeof (header));
header[0] = 0x84; /* 0x80 = Last metadata block,
* 0x04 = vorbiscomment block */
buffer = gst_tag_list_to_vorbiscomment_buffer (merged_tags, header,
sizeof (header), NULL);
GST_DEBUG_OBJECT (tag, "Writing tags %" GST_PTR_FORMAT, merged_tags);
gst_tag_list_unref (merged_tags);
if (buffer == NULL)
goto no_comment;
size = gst_buffer_get_size (buffer);
if ((size < 4) || ((size - 4) > 0xFFFFFF))
goto comment_too_long;
fbit[0] = 1;
/* Get rid of the framing bit at the end of the vorbiscomment buffer
* if it exists since libFLAC seems to lose sync because of this
* bit in gstflacdec
*/
if (gst_buffer_memcmp (buffer, size - 1, fbit, 1) == 0) {
buffer = gst_buffer_make_writable (buffer);
gst_buffer_resize (buffer, 0, size - 1);
}
}
/* The 4 byte metadata block header isn't accounted for in the total
* size of the metadata block
*/
gst_buffer_map (buffer, &map, GST_MAP_WRITE);
map.data[1] = (((map.size - 4) & 0xFF0000) >> 16);
map.data[2] = (((map.size - 4) & 0x00FF00) >> 8);
map.data[3] = ((map.size - 4) & 0x0000FF);
gst_buffer_unmap (buffer, &map);
GST_DEBUG_OBJECT (tag, "pushing %" G_GSIZE_FORMAT " byte vorbiscomment "
"buffer", map.size);
ret = gst_pad_push (tag->srcpad, buffer);
if (ret != GST_FLOW_OK) {
goto cleanup;
}
tag->state = GST_FLAC_TAG_STATE_AUDIO_DATA;
}
/* The metadata blocks have been read, now we are reading audio data */
if (tag->state == GST_FLAC_TAG_STATE_AUDIO_DATA) {
GstBuffer *buffer;
guint avail;
avail = gst_adapter_available (tag->adapter);
if (avail > 0) {
buffer = gst_adapter_take_buffer (tag->adapter, avail);
ret = gst_pad_push (tag->srcpad, buffer);
}
}
cleanup:
GST_LOG_OBJECT (pad, "state: %d, ret: %d", tag->state, ret);
return ret;
/* ERRORS */
no_buffer:
{
GST_ELEMENT_ERROR (tag, CORE, TOO_LAZY, (NULL),
("Error creating 12-byte buffer for padding block"));
ret = GST_FLOW_ERROR;
goto cleanup;
}
no_comment:
{
GST_ELEMENT_ERROR (tag, CORE, TAG, (NULL),
("Error converting tag list to vorbiscomment buffer"));
ret = GST_FLOW_ERROR;
goto cleanup;
}
comment_too_long:
{
/* FLAC vorbis comment blocks are limited to 2^24 bytes,
* while the vorbis specs allow more than that. Shouldn't
* be a real world problem though
*/
GST_ELEMENT_ERROR (tag, CORE, TAG, (NULL),
("Vorbis comment of size %" G_GSIZE_FORMAT " too long", size));
ret = GST_FLOW_ERROR;
goto cleanup;
}
}
static GstStateChangeReturn
gst_flac_tag_change_state (GstElement * element, GstStateChange transition)
{
GstFlacTag *tag;
tag = GST_FLAC_TAG (element);
switch (transition) {
case GST_STATE_CHANGE_NULL_TO_READY:
break;
case GST_STATE_CHANGE_READY_TO_PAUSED:
break;
case GST_STATE_CHANGE_PAUSED_TO_PLAYING:
/* do something to get out of the chain function faster */
break;
case GST_STATE_CHANGE_PLAYING_TO_PAUSED:
break;
case GST_STATE_CHANGE_PAUSED_TO_READY:
gst_adapter_clear (tag->adapter);
if (tag->vorbiscomment) {
gst_buffer_unref (tag->vorbiscomment);
tag->vorbiscomment = NULL;
}
if (tag->tags) {
gst_tag_list_unref (tag->tags);
tag->tags = NULL;
}
tag->metadata_block_size = 0;
tag->metadata_last_block = FALSE;
tag->state = GST_FLAC_TAG_STATE_INIT;
break;
case GST_STATE_CHANGE_READY_TO_NULL:
break;
default:
break;
}
return GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
}