1 /* GStreamer Opus Encoder
2 * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
3 * Copyright (C) <2008> Sebastian Dröge <sebastian.droege@collabora.co.uk>
4 * Copyright (C) <2011> Vincent Penquerc'h <vincent.penquerch@collabora.co.uk>
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Library General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Library General Public License for more details.
16 * You should have received a copy of the GNU Library General Public
17 * License along with this library; if not, write to the
18 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 * Boston, MA 02111-1307, USA.
25 #include <gst/tag/tag.h>
26 #include <gst/base/gstbytewriter.h>
27 #include "gstopusheader.h"
30 gst_opus_enc_create_id_buffer (gint nchannels, gint n_stereo_streams,
31 gint sample_rate, guint8 channel_mapping_family,
32 const guint8 * channel_mapping)
38 g_return_val_if_fail (nchannels > 0 && nchannels < 256, NULL);
39 g_return_val_if_fail (n_stereo_streams >= 0, NULL);
40 g_return_val_if_fail (n_stereo_streams <= nchannels - n_stereo_streams, NULL);
42 gst_byte_writer_init (&bw);
44 /* See http://wiki.xiph.org/OggOpus */
45 hdl &= gst_byte_writer_put_data (&bw, (const guint8 *) "OpusHead", 8);
46 hdl &= gst_byte_writer_put_uint8 (&bw, 0x01); /* version number */
47 hdl &= gst_byte_writer_put_uint8 (&bw, nchannels);
48 hdl &= gst_byte_writer_put_uint16_le (&bw, 0); /* pre-skip */
49 hdl &= gst_byte_writer_put_uint32_le (&bw, sample_rate);
50 hdl &= gst_byte_writer_put_uint16_le (&bw, 0); /* output gain */
51 hdl &= gst_byte_writer_put_uint8 (&bw, channel_mapping_family);
52 if (channel_mapping_family > 0) {
53 hdl &= gst_byte_writer_put_uint8 (&bw, nchannels - n_stereo_streams);
54 hdl &= gst_byte_writer_put_uint8 (&bw, n_stereo_streams);
55 hdl &= gst_byte_writer_put_data (&bw, channel_mapping, nchannels);
59 GST_WARNING ("Error creating header");
61 buffer = gst_byte_writer_reset_and_get_buffer (&bw);
63 GST_BUFFER_OFFSET (buffer) = 0;
64 GST_BUFFER_OFFSET_END (buffer) = 0;
70 gst_opus_enc_create_metadata_buffer (const GstTagList * tags)
72 GstTagList *empty_tags = NULL;
73 GstBuffer *comments = NULL;
75 GST_DEBUG ("tags = %" GST_PTR_FORMAT, tags);
78 /* FIXME: better fix chain of callers to not write metadata at all,
80 empty_tags = gst_tag_list_new_empty ();
84 gst_tag_list_to_vorbiscomment_buffer (tags, (const guint8 *) "OpusTags",
85 8, "Encoded with GStreamer Opusenc");
87 GST_BUFFER_OFFSET (comments) = 0;
88 GST_BUFFER_OFFSET_END (comments) = 0;
91 gst_tag_list_free (empty_tags);
97 * (really really) FIXME: move into core (dixit tpm)
100 * _gst_caps_set_buffer_array:
102 * @field: field in caps to set
103 * @buf: header buffers
105 * Adds given buffers to an array of buffers set as the given @field
106 * on the given @caps. List of buffer arguments must be NULL-terminated.
108 * Returns: input caps with a streamheader field added, or NULL if some error
111 _gst_caps_set_buffer_array (GstCaps * caps, const gchar * field,
112 GstBuffer * buf, ...)
114 GstStructure *structure = NULL;
116 GValue array = { 0 };
117 GValue value = { 0 };
119 g_return_val_if_fail (caps != NULL, NULL);
120 g_return_val_if_fail (gst_caps_is_fixed (caps), NULL);
121 g_return_val_if_fail (field != NULL, NULL);
123 caps = gst_caps_make_writable (caps);
124 structure = gst_caps_get_structure (caps, 0);
126 g_value_init (&array, GST_TYPE_ARRAY);
129 /* put buffers in a fixed list */
131 g_assert (gst_buffer_is_writable (buf));
134 GST_BUFFER_FLAG_SET (buf, GST_BUFFER_FLAG_HEADER);
136 g_value_init (&value, GST_TYPE_BUFFER);
137 buf = gst_buffer_copy (buf);
138 GST_BUFFER_FLAG_SET (buf, GST_BUFFER_FLAG_HEADER);
139 gst_value_set_buffer (&value, buf);
140 gst_buffer_unref (buf);
141 gst_value_array_append_value (&array, &value);
142 g_value_unset (&value);
144 buf = va_arg (va, GstBuffer *);
147 gst_structure_set_value (structure, field, &array);
148 g_value_unset (&array);
154 gst_opus_header_create_caps_from_headers (GstCaps ** caps, GSList ** headers,
155 GstBuffer * buf1, GstBuffer * buf2)
157 int n_streams, family;
158 gboolean multistream;
162 g_return_if_fail (caps);
163 g_return_if_fail (headers && !*headers);
164 g_return_if_fail (gst_buffer_get_size (buf1) >= 19);
166 gst_buffer_map (buf1, &map, GST_MAP_READ);
169 /* work out the number of streams */
174 /* only included in the header for family > 0 */
176 n_streams = data[19];
178 g_warning ("family > 0 but header buffer size < 20");
179 gst_buffer_unmap (buf1, &map);
184 gst_buffer_unmap (buf1, &map);
186 /* mark and put on caps */
187 multistream = n_streams > 1;
188 *caps = gst_caps_new_simple ("audio/x-opus",
189 "multistream", G_TYPE_BOOLEAN, multistream, NULL);
190 *caps = _gst_caps_set_buffer_array (*caps, "streamheader", buf1, buf2, NULL);
192 *headers = g_slist_prepend (*headers, buf2);
193 *headers = g_slist_prepend (*headers, buf1);
197 gst_opus_header_create_caps (GstCaps ** caps, GSList ** headers, gint nchannels,
198 gint n_stereo_streams, gint sample_rate, guint8 channel_mapping_family,
199 const guint8 * channel_mapping, const GstTagList * tags)
201 GstBuffer *buf1, *buf2;
203 g_return_if_fail (caps);
204 g_return_if_fail (headers && !*headers);
205 g_return_if_fail (nchannels > 0);
206 g_return_if_fail (sample_rate >= 0); /* 0 -> unset */
207 g_return_if_fail (channel_mapping_family == 0 || channel_mapping);
209 /* Opus streams in Ogg begin with two headers; the initial header (with
210 most of the codec setup parameters) which is mandated by the Ogg
211 bitstream spec. The second header holds any comment fields. */
213 /* create header buffers */
215 gst_opus_enc_create_id_buffer (nchannels, n_stereo_streams, sample_rate,
216 channel_mapping_family, channel_mapping);
217 buf2 = gst_opus_enc_create_metadata_buffer (tags);
219 gst_opus_header_create_caps_from_headers (caps, headers, buf1, buf2);
223 gst_opus_header_is_header (GstBuffer * buf, const char *magic, guint magic_size)
225 return (gst_buffer_get_size (buf) >= magic_size
226 && !gst_buffer_memcmp (buf, 0, magic, magic_size));
230 gst_opus_header_is_id_header (GstBuffer * buf)
232 gsize size = gst_buffer_get_size (buf);
234 guint8 channels, channel_mapping_family, n_streams, n_stereo_streams;
235 gboolean ret = FALSE;
240 if (!gst_opus_header_is_header (buf, "OpusHead", 8))
243 gst_buffer_map (buf, &map, GST_MAP_READ);
252 channel_mapping_family = data[18];
254 if (channel_mapping_family == 0) {
259 if (size < 21 + channels)
261 n_streams = data[19];
262 n_stereo_streams = data[20];
265 if (n_stereo_streams > n_streams)
267 if (n_streams + n_stereo_streams > 255)
274 gst_buffer_unmap (buf, &map);
279 gst_opus_header_is_comment_header (GstBuffer * buf)
281 return gst_opus_header_is_header (buf, "OpusTags", 8);