2 * LPCM codecs for PCM formats found in MPEG streams
3 * Copyright (c) 2009 Christian Schmidt
5 * This file is part of Libav.
7 * Libav is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * Libav is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 * PCM codecs for encodings found in MPEG streams (DVD/Blu-ray)
27 #include "libavutil/audioconvert.h"
29 #include "bytestream.h"
32 * Channel Mapping according to
33 * Blu-ray Disc Read-Only Format Version 1
34 * Part 3: Audio Visual Basic Specifications
42 * 3/2+lfe L R C LS RS lfe
43 * 3/4 L R C LS Rls Rrs RS X
44 * 3/4+lfe L R C LS Rls Rrs RS lfe
48 * Parse the header of a LPCM frame read from a MPEG-TS stream
49 * @param avctx the codec context
50 * @param header pointer to the first four bytes of the data packet
52 static int pcm_bluray_parse_header(AVCodecContext *avctx,
53 const uint8_t *header)
55 static const uint8_t bits_per_samples[4] = { 0, 16, 20, 24 };
56 static const uint32_t channel_layouts[16] = {
57 0, AV_CH_LAYOUT_MONO, 0, AV_CH_LAYOUT_STEREO, AV_CH_LAYOUT_SURROUND,
58 AV_CH_LAYOUT_2_1, AV_CH_LAYOUT_4POINT0, AV_CH_LAYOUT_2_2, AV_CH_LAYOUT_5POINT0,
59 AV_CH_LAYOUT_5POINT1, AV_CH_LAYOUT_7POINT0, AV_CH_LAYOUT_7POINT1, 0, 0, 0, 0
61 static const uint8_t channels[16] = {
62 0, 1, 0, 2, 3, 3, 4, 4, 5, 6, 7, 8, 0, 0, 0, 0
64 uint8_t channel_layout = header[2] >> 4;
66 if (avctx->debug & FF_DEBUG_PICT_INFO)
67 av_dlog(avctx, "pcm_bluray_parse_header: header = %02x%02x%02x%02x\n",
68 header[0], header[1], header[2], header[3]);
70 /* get the sample depth and derive the sample format from it */
71 avctx->bits_per_coded_sample = bits_per_samples[header[3] >> 6];
72 if (!avctx->bits_per_coded_sample) {
73 av_log(avctx, AV_LOG_ERROR, "unsupported sample depth (0)\n");
76 avctx->sample_fmt = avctx->bits_per_coded_sample == 16 ? AV_SAMPLE_FMT_S16 :
79 /* get the sample rate. Not all values are known or exist. */
80 switch (header[2] & 0x0f) {
82 avctx->sample_rate = 48000;
85 avctx->sample_rate = 96000;
88 avctx->sample_rate = 192000;
91 avctx->sample_rate = 0;
92 av_log(avctx, AV_LOG_ERROR, "unsupported sample rate (%d)\n",
98 * get the channel number (and mapping). Not all values are known or exist.
99 * It must be noted that the number of channels in the MPEG stream can
100 * differ from the actual meaningful number, e.g. mono audio still has two
101 * channels, one being empty.
103 avctx->channel_layout = channel_layouts[channel_layout];
104 avctx->channels = channels[channel_layout];
105 if (!avctx->channels) {
106 av_log(avctx, AV_LOG_ERROR, "unsupported channel configuration (%d)\n",
111 avctx->bit_rate = avctx->channels * avctx->sample_rate *
112 avctx->bits_per_coded_sample;
114 if (avctx->debug & FF_DEBUG_PICT_INFO)
116 "pcm_bluray_parse_header: %d channels, %d bits per sample, %d kHz, %d kbit\n",
117 avctx->channels, avctx->bits_per_coded_sample,
118 avctx->sample_rate, avctx->bit_rate);
122 typedef struct PCMBRDecode {
126 static av_cold int pcm_bluray_decode_init(AVCodecContext * avctx)
128 PCMBRDecode *s = avctx->priv_data;
130 avcodec_get_frame_defaults(&s->frame);
131 avctx->coded_frame = &s->frame;
136 static int pcm_bluray_decode_frame(AVCodecContext *avctx, void *data,
137 int *got_frame_ptr, AVPacket *avpkt)
139 const uint8_t *src = avpkt->data;
140 int buf_size = avpkt->size;
141 PCMBRDecode *s = avctx->priv_data;
143 int num_source_channels, channel, retval;
144 int sample_size, samples;
149 av_log(avctx, AV_LOG_ERROR, "PCM packet too small\n");
153 if (pcm_bluray_parse_header(avctx, src))
158 bytestream2_init(&gb, src, buf_size);
160 /* There's always an even number of channels in the source */
161 num_source_channels = FFALIGN(avctx->channels, 2);
162 sample_size = (num_source_channels * (avctx->sample_fmt == AV_SAMPLE_FMT_S16 ? 16 : 24)) >> 3;
163 samples = buf_size / sample_size;
165 /* get output buffer */
166 s->frame.nb_samples = samples;
167 if ((retval = avctx->get_buffer(avctx, &s->frame)) < 0) {
168 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
171 dst16 = (int16_t *)s->frame.data[0];
172 dst32 = (int32_t *)s->frame.data[0];
175 switch (avctx->channel_layout) {
176 /* cases with same number of source and coded channels */
177 case AV_CH_LAYOUT_STEREO:
178 case AV_CH_LAYOUT_4POINT0:
179 case AV_CH_LAYOUT_2_2:
180 samples *= num_source_channels;
181 if (AV_SAMPLE_FMT_S16 == avctx->sample_fmt) {
183 bytestream2_get_buffer(&gb, dst16, buf_size);
186 *dst16++ = bytestream2_get_be16u(&gb);
191 *dst32++ = bytestream2_get_be24u(&gb) << 8;
195 /* cases where number of source channels = coded channels + 1 */
196 case AV_CH_LAYOUT_MONO:
197 case AV_CH_LAYOUT_SURROUND:
198 case AV_CH_LAYOUT_2_1:
199 case AV_CH_LAYOUT_5POINT0:
200 if (AV_SAMPLE_FMT_S16 == avctx->sample_fmt) {
203 bytestream2_get_buffer(&gb, dst16, avctx->channels * 2);
204 dst16 += avctx->channels;
206 channel = avctx->channels;
208 *dst16++ = bytestream2_get_be16u(&gb);
211 bytestream2_skip(&gb, 2);
215 channel = avctx->channels;
217 *dst32++ = bytestream2_get_be24u(&gb) << 8;
219 bytestream2_skip(&gb, 3);
223 /* remapping: L, R, C, LBack, RBack, LF */
224 case AV_CH_LAYOUT_5POINT1:
225 if (AV_SAMPLE_FMT_S16 == avctx->sample_fmt) {
227 dst16[0] = bytestream2_get_be16u(&gb);
228 dst16[1] = bytestream2_get_be16u(&gb);
229 dst16[2] = bytestream2_get_be16u(&gb);
230 dst16[4] = bytestream2_get_be16u(&gb);
231 dst16[5] = bytestream2_get_be16u(&gb);
232 dst16[3] = bytestream2_get_be16u(&gb);
237 dst32[0] = bytestream2_get_be24u(&gb) << 8;
238 dst32[1] = bytestream2_get_be24u(&gb) << 8;
239 dst32[2] = bytestream2_get_be24u(&gb) << 8;
240 dst32[4] = bytestream2_get_be24u(&gb) << 8;
241 dst32[5] = bytestream2_get_be24u(&gb) << 8;
242 dst32[3] = bytestream2_get_be24u(&gb) << 8;
247 /* remapping: L, R, C, LSide, LBack, RBack, RSide, <unused> */
248 case AV_CH_LAYOUT_7POINT0:
249 if (AV_SAMPLE_FMT_S16 == avctx->sample_fmt) {
251 dst16[0] = bytestream2_get_be16u(&gb);
252 dst16[1] = bytestream2_get_be16u(&gb);
253 dst16[2] = bytestream2_get_be16u(&gb);
254 dst16[5] = bytestream2_get_be16u(&gb);
255 dst16[3] = bytestream2_get_be16u(&gb);
256 dst16[4] = bytestream2_get_be16u(&gb);
257 dst16[6] = bytestream2_get_be16u(&gb);
259 bytestream2_skip(&gb, 2);
263 dst32[0] = bytestream2_get_be24u(&gb) << 8;
264 dst32[1] = bytestream2_get_be24u(&gb) << 8;
265 dst32[2] = bytestream2_get_be24u(&gb) << 8;
266 dst32[5] = bytestream2_get_be24u(&gb) << 8;
267 dst32[3] = bytestream2_get_be24u(&gb) << 8;
268 dst32[4] = bytestream2_get_be24u(&gb) << 8;
269 dst32[6] = bytestream2_get_be24u(&gb) << 8;
271 bytestream2_skip(&gb, 3);
275 /* remapping: L, R, C, LSide, LBack, RBack, RSide, LF */
276 case AV_CH_LAYOUT_7POINT1:
277 if (AV_SAMPLE_FMT_S16 == avctx->sample_fmt) {
279 dst16[0] = bytestream2_get_be16u(&gb);
280 dst16[1] = bytestream2_get_be16u(&gb);
281 dst16[2] = bytestream2_get_be16u(&gb);
282 dst16[6] = bytestream2_get_be16u(&gb);
283 dst16[4] = bytestream2_get_be16u(&gb);
284 dst16[5] = bytestream2_get_be16u(&gb);
285 dst16[7] = bytestream2_get_be16u(&gb);
286 dst16[3] = bytestream2_get_be16u(&gb);
291 dst32[0] = bytestream2_get_be24u(&gb) << 8;
292 dst32[1] = bytestream2_get_be24u(&gb) << 8;
293 dst32[2] = bytestream2_get_be24u(&gb) << 8;
294 dst32[6] = bytestream2_get_be24u(&gb) << 8;
295 dst32[4] = bytestream2_get_be24u(&gb) << 8;
296 dst32[5] = bytestream2_get_be24u(&gb) << 8;
297 dst32[7] = bytestream2_get_be24u(&gb) << 8;
298 dst32[3] = bytestream2_get_be24u(&gb) << 8;
307 *(AVFrame *)data = s->frame;
309 retval = bytestream2_tell(&gb);
310 if (avctx->debug & FF_DEBUG_BITSTREAM)
311 av_dlog(avctx, "pcm_bluray_decode_frame: decoded %d -> %d bytes\n",
316 AVCodec ff_pcm_bluray_decoder = {
317 .name = "pcm_bluray",
318 .type = AVMEDIA_TYPE_AUDIO,
319 .id = CODEC_ID_PCM_BLURAY,
320 .priv_data_size = sizeof(PCMBRDecode),
321 .init = pcm_bluray_decode_init,
322 .decode = pcm_bluray_decode_frame,
323 .capabilities = CODEC_CAP_DR1,
324 .sample_fmts = (const enum AVSampleFormat[]){AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_S32,
326 .long_name = NULL_IF_CONFIG_SMALL("PCM signed 16|20|24-bit big-endian for Blu-ray media"),