gstreamer/ext/opus/gstopusheader.c
2012-05-24 22:59:09 +01:00

286 lines
8.1 KiB
C

/* GStreamer Opus Encoder
* Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
* Copyright (C) <2008> Sebastian Dröge <sebastian.droege@collabora.co.uk>
* Copyright (C) <2011> Vincent Penquerc'h <vincent.penquerch@collabora.co.uk>
*
* 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., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gst/tag/tag.h>
#include <gst/base/gstbytewriter.h>
#include "gstopusheader.h"
static GstBuffer *
gst_opus_enc_create_id_buffer (gint nchannels, gint n_stereo_streams,
gint sample_rate, guint8 channel_mapping_family,
const guint8 * channel_mapping)
{
GstBuffer *buffer;
GstByteWriter bw;
gboolean hdl = TRUE;
g_return_val_if_fail (nchannels > 0 && nchannels < 256, NULL);
g_return_val_if_fail (n_stereo_streams >= 0, NULL);
g_return_val_if_fail (n_stereo_streams <= nchannels - n_stereo_streams, NULL);
gst_byte_writer_init (&bw);
/* See http://wiki.xiph.org/OggOpus */
hdl &= gst_byte_writer_put_data (&bw, (const guint8 *) "OpusHead", 8);
hdl &= gst_byte_writer_put_uint8 (&bw, 0x01); /* version number */
hdl &= gst_byte_writer_put_uint8 (&bw, nchannels);
hdl &= gst_byte_writer_put_uint16_le (&bw, 0); /* pre-skip */
hdl &= gst_byte_writer_put_uint32_le (&bw, sample_rate);
hdl &= gst_byte_writer_put_uint16_le (&bw, 0); /* output gain */
hdl &= gst_byte_writer_put_uint8 (&bw, channel_mapping_family);
if (channel_mapping_family > 0) {
hdl &= gst_byte_writer_put_uint8 (&bw, nchannels - n_stereo_streams);
hdl &= gst_byte_writer_put_uint8 (&bw, n_stereo_streams);
hdl &= gst_byte_writer_put_data (&bw, channel_mapping, nchannels);
}
if (!hdl)
GST_WARNING ("Error creating header");
buffer = gst_byte_writer_reset_and_get_buffer (&bw);
GST_BUFFER_OFFSET (buffer) = 0;
GST_BUFFER_OFFSET_END (buffer) = 0;
return buffer;
}
static GstBuffer *
gst_opus_enc_create_metadata_buffer (const GstTagList * tags)
{
GstTagList *empty_tags = NULL;
GstBuffer *comments = NULL;
GST_DEBUG ("tags = %" GST_PTR_FORMAT, tags);
if (tags == NULL) {
/* FIXME: better fix chain of callers to not write metadata at all,
* if there is none */
empty_tags = gst_tag_list_new_empty ();
tags = empty_tags;
}
comments =
gst_tag_list_to_vorbiscomment_buffer (tags, (const guint8 *) "OpusTags",
8, "Encoded with GStreamer Opusenc");
GST_BUFFER_OFFSET (comments) = 0;
GST_BUFFER_OFFSET_END (comments) = 0;
if (empty_tags)
gst_tag_list_free (empty_tags);
return comments;
}
/*
* (really really) FIXME: move into core (dixit tpm)
*/
/**
* _gst_caps_set_buffer_array:
* @caps: a #GstCaps
* @field: field in caps to set
* @buf: header buffers
*
* Adds given buffers to an array of buffers set as the given @field
* on the given @caps. List of buffer arguments must be NULL-terminated.
*
* Returns: input caps with a streamheader field added, or NULL if some error
*/
static GstCaps *
_gst_caps_set_buffer_array (GstCaps * caps, const gchar * field,
GstBuffer * buf, ...)
{
GstStructure *structure = NULL;
va_list va;
GValue array = { 0 };
GValue value = { 0 };
g_return_val_if_fail (caps != NULL, NULL);
g_return_val_if_fail (gst_caps_is_fixed (caps), NULL);
g_return_val_if_fail (field != NULL, NULL);
caps = gst_caps_make_writable (caps);
structure = gst_caps_get_structure (caps, 0);
g_value_init (&array, GST_TYPE_ARRAY);
va_start (va, buf);
/* put buffers in a fixed list */
while (buf) {
g_assert (gst_buffer_is_writable (buf));
/* mark buffer */
GST_BUFFER_FLAG_SET (buf, GST_BUFFER_FLAG_HEADER);
g_value_init (&value, GST_TYPE_BUFFER);
buf = gst_buffer_copy (buf);
GST_BUFFER_FLAG_SET (buf, GST_BUFFER_FLAG_HEADER);
gst_value_set_buffer (&value, buf);
gst_buffer_unref (buf);
gst_value_array_append_value (&array, &value);
g_value_unset (&value);
buf = va_arg (va, GstBuffer *);
}
gst_structure_set_value (structure, field, &array);
g_value_unset (&array);
return caps;
}
void
gst_opus_header_create_caps_from_headers (GstCaps ** caps, GSList ** headers,
GstBuffer * buf1, GstBuffer * buf2)
{
int n_streams, family;
gboolean multistream;
GstMapInfo map;
guint8 *data;
g_return_if_fail (caps);
g_return_if_fail (headers && !*headers);
g_return_if_fail (gst_buffer_get_size (buf1) >= 19);
gst_buffer_map (buf1, &map, GST_MAP_READ);
data = map.data;
/* work out the number of streams */
family = data[18];
if (family == 0) {
n_streams = 1;
} else {
/* only included in the header for family > 0 */
if (map.size >= 20)
n_streams = data[19];
else {
g_warning ("family > 0 but header buffer size < 20");
gst_buffer_unmap (buf1, &map);
return;
}
}
gst_buffer_unmap (buf1, &map);
/* mark and put on caps */
multistream = n_streams > 1;
*caps = gst_caps_new_simple ("audio/x-opus",
"multistream", G_TYPE_BOOLEAN, multistream, NULL);
*caps = _gst_caps_set_buffer_array (*caps, "streamheader", buf1, buf2, NULL);
*headers = g_slist_prepend (*headers, buf2);
*headers = g_slist_prepend (*headers, buf1);
}
void
gst_opus_header_create_caps (GstCaps ** caps, GSList ** headers, gint nchannels,
gint n_stereo_streams, gint sample_rate, guint8 channel_mapping_family,
const guint8 * channel_mapping, const GstTagList * tags)
{
GstBuffer *buf1, *buf2;
g_return_if_fail (caps);
g_return_if_fail (headers && !*headers);
g_return_if_fail (nchannels > 0);
g_return_if_fail (sample_rate >= 0); /* 0 -> unset */
g_return_if_fail (channel_mapping_family == 0 || channel_mapping);
/* Opus streams in Ogg begin with two headers; the initial header (with
most of the codec setup parameters) which is mandated by the Ogg
bitstream spec. The second header holds any comment fields. */
/* create header buffers */
buf1 =
gst_opus_enc_create_id_buffer (nchannels, n_stereo_streams, sample_rate,
channel_mapping_family, channel_mapping);
buf2 = gst_opus_enc_create_metadata_buffer (tags);
gst_opus_header_create_caps_from_headers (caps, headers, buf1, buf2);
}
gboolean
gst_opus_header_is_header (GstBuffer * buf, const char *magic, guint magic_size)
{
return (gst_buffer_get_size (buf) >= magic_size
&& !gst_buffer_memcmp (buf, 0, magic, magic_size));
}
gboolean
gst_opus_header_is_id_header (GstBuffer * buf)
{
gsize size = gst_buffer_get_size (buf);
guint8 *data = NULL;
guint8 version, channels, channel_mapping_family, n_streams, n_stereo_streams;
gboolean ret = FALSE;
GstMapInfo map;
if (size < 19)
goto beach;
if (!gst_opus_header_is_header (buf, "OpusHead", 8))
goto beach;
gst_buffer_map (buf, &map, GST_MAP_READ);
data = map.data;
size = map.size;
version = data[8];
if (version >= 0x0f) /* major version >=0 is what we grok */
goto beach;
channels = data[9];
if (channels == 0)
goto beach;
channel_mapping_family = data[18];
if (channel_mapping_family == 0) {
if (channels > 2)
goto beach;
} else {
channels = data[9];
if (size < 21 + channels)
goto beach;
n_streams = data[19];
n_stereo_streams = data[20];
if (n_streams == 0)
goto beach;
if (n_stereo_streams > n_streams)
goto beach;
if (n_streams + n_stereo_streams > 255)
goto beach;
}
ret = TRUE;
beach:
if (data)
gst_buffer_unmap (buf, &map);
return ret;
}
gboolean
gst_opus_header_is_comment_header (GstBuffer * buf)
{
return gst_opus_header_is_header (buf, "OpusTags", 8);
}