2 * LPCM codecs for PCM formats found in MPEG streams
3 * Copyright (c) 2009 Christian Schmidt
5 * This file is part of FFmpeg.
7 * FFmpeg 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 * FFmpeg 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 FFmpeg; 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/channel_layout.h"
29 #include "bytestream.h"
33 * Channel Mapping according to
34 * Blu-ray Disc Read-Only Format Version 1
35 * Part 3: Audio Visual Basic Specifications
43 * 3/2+lfe L R C LS RS lfe
44 * 3/4 L R C LS Rls Rrs RS X
45 * 3/4+lfe L R C LS Rls Rrs RS lfe
49 * Parse the header of a LPCM frame read from a MPEG-TS stream
50 * @param avctx the codec context
51 * @param header pointer to the first four bytes of the data packet
53 static int pcm_bluray_parse_header(AVCodecContext *avctx,
54 const uint8_t *header)
56 static const uint8_t bits_per_samples[4] = { 0, 16, 20, 24 };
57 static const uint32_t channel_layouts[16] = {
58 0, AV_CH_LAYOUT_MONO, 0, AV_CH_LAYOUT_STEREO, AV_CH_LAYOUT_SURROUND,
59 AV_CH_LAYOUT_2_1, AV_CH_LAYOUT_4POINT0, AV_CH_LAYOUT_2_2, AV_CH_LAYOUT_5POINT0,
60 AV_CH_LAYOUT_5POINT1, AV_CH_LAYOUT_7POINT0, AV_CH_LAYOUT_7POINT1, 0, 0, 0, 0
62 static const uint8_t channels[16] = {
63 0, 1, 0, 2, 3, 3, 4, 4, 5, 6, 7, 8, 0, 0, 0, 0
65 uint8_t channel_layout = header[2] >> 4;
67 if (avctx->debug & FF_DEBUG_PICT_INFO)
68 av_dlog(avctx, "pcm_bluray_parse_header: header = %02x%02x%02x%02x\n",
69 header[0], header[1], header[2], header[3]);
71 /* get the sample depth and derive the sample format from it */
72 avctx->bits_per_coded_sample = bits_per_samples[header[3] >> 6];
73 if (!(avctx->bits_per_coded_sample == 16 || avctx->bits_per_coded_sample == 24)) {
74 av_log(avctx, AV_LOG_ERROR, "unsupported sample depth (%d)\n", avctx->bits_per_coded_sample);
77 avctx->sample_fmt = avctx->bits_per_coded_sample == 16 ? AV_SAMPLE_FMT_S16 :
79 if (avctx->sample_fmt == AV_SAMPLE_FMT_S32)
80 avctx->bits_per_raw_sample = avctx->bits_per_coded_sample;
82 /* get the sample rate. Not all values are used. */
83 switch (header[2] & 0x0f) {
85 avctx->sample_rate = 48000;
88 avctx->sample_rate = 96000;
91 avctx->sample_rate = 192000;
94 avctx->sample_rate = 0;
95 av_log(avctx, AV_LOG_ERROR, "reserved sample rate (%d)\n",
101 * get the channel number (and mapping). Not all values are used.
102 * It must be noted that the number of channels in the MPEG stream can
103 * differ from the actual meaningful number, e.g. mono audio still has two
104 * channels, one being empty.
106 avctx->channel_layout = channel_layouts[channel_layout];
107 avctx->channels = channels[channel_layout];
108 if (!avctx->channels) {
109 av_log(avctx, AV_LOG_ERROR, "reserved channel configuration (%d)\n",
114 avctx->bit_rate = FFALIGN(avctx->channels, 2) * avctx->sample_rate *
115 avctx->bits_per_coded_sample;
117 if (avctx->debug & FF_DEBUG_PICT_INFO)
119 "pcm_bluray_parse_header: %d channels, %d bits per sample, %d Hz, %d bit/s\n",
120 avctx->channels, avctx->bits_per_coded_sample,
121 avctx->sample_rate, avctx->bit_rate);
125 static int pcm_bluray_decode_frame(AVCodecContext *avctx, void *data,
126 int *got_frame_ptr, AVPacket *avpkt)
128 AVFrame *frame = data;
129 const uint8_t *src = avpkt->data;
130 int buf_size = avpkt->size;
132 int num_source_channels, channel, retval;
133 int sample_size, samples;
138 av_log(avctx, AV_LOG_ERROR, "PCM packet too small\n");
142 if (pcm_bluray_parse_header(avctx, src))
147 bytestream2_init(&gb, src, buf_size);
149 /* There's always an even number of channels in the source */
150 num_source_channels = FFALIGN(avctx->channels, 2);
151 sample_size = (num_source_channels * (avctx->sample_fmt == AV_SAMPLE_FMT_S16 ? 16 : 24)) >> 3;
152 samples = buf_size / sample_size;
154 /* get output buffer */
155 frame->nb_samples = samples;
156 if ((retval = ff_get_buffer(avctx, frame, 0)) < 0)
158 dst16 = (int16_t *)frame->data[0];
159 dst32 = (int32_t *)frame->data[0];
162 switch (avctx->channel_layout) {
163 /* cases with same number of source and coded channels */
164 case AV_CH_LAYOUT_STEREO:
165 case AV_CH_LAYOUT_4POINT0:
166 case AV_CH_LAYOUT_2_2:
167 samples *= num_source_channels;
168 if (AV_SAMPLE_FMT_S16 == avctx->sample_fmt) {
170 bytestream2_get_buffer(&gb, dst16, buf_size);
173 *dst16++ = bytestream2_get_be16u(&gb);
178 *dst32++ = bytestream2_get_be24u(&gb) << 8;
182 /* cases where number of source channels = coded channels + 1 */
183 case AV_CH_LAYOUT_MONO:
184 case AV_CH_LAYOUT_SURROUND:
185 case AV_CH_LAYOUT_2_1:
186 case AV_CH_LAYOUT_5POINT0:
187 if (AV_SAMPLE_FMT_S16 == avctx->sample_fmt) {
190 bytestream2_get_buffer(&gb, dst16, avctx->channels * 2);
191 dst16 += avctx->channels;
193 channel = avctx->channels;
195 *dst16++ = bytestream2_get_be16u(&gb);
198 bytestream2_skip(&gb, 2);
202 channel = avctx->channels;
204 *dst32++ = bytestream2_get_be24u(&gb) << 8;
206 bytestream2_skip(&gb, 3);
210 /* remapping: L, R, C, LBack, RBack, LF */
211 case AV_CH_LAYOUT_5POINT1:
212 if (AV_SAMPLE_FMT_S16 == avctx->sample_fmt) {
214 dst16[0] = bytestream2_get_be16u(&gb);
215 dst16[1] = bytestream2_get_be16u(&gb);
216 dst16[2] = bytestream2_get_be16u(&gb);
217 dst16[4] = bytestream2_get_be16u(&gb);
218 dst16[5] = bytestream2_get_be16u(&gb);
219 dst16[3] = bytestream2_get_be16u(&gb);
224 dst32[0] = bytestream2_get_be24u(&gb) << 8;
225 dst32[1] = bytestream2_get_be24u(&gb) << 8;
226 dst32[2] = bytestream2_get_be24u(&gb) << 8;
227 dst32[4] = bytestream2_get_be24u(&gb) << 8;
228 dst32[5] = bytestream2_get_be24u(&gb) << 8;
229 dst32[3] = bytestream2_get_be24u(&gb) << 8;
234 /* remapping: L, R, C, LSide, LBack, RBack, RSide, <unused> */
235 case AV_CH_LAYOUT_7POINT0:
236 if (AV_SAMPLE_FMT_S16 == avctx->sample_fmt) {
238 dst16[0] = bytestream2_get_be16u(&gb);
239 dst16[1] = bytestream2_get_be16u(&gb);
240 dst16[2] = bytestream2_get_be16u(&gb);
241 dst16[5] = bytestream2_get_be16u(&gb);
242 dst16[3] = bytestream2_get_be16u(&gb);
243 dst16[4] = bytestream2_get_be16u(&gb);
244 dst16[6] = bytestream2_get_be16u(&gb);
246 bytestream2_skip(&gb, 2);
250 dst32[0] = bytestream2_get_be24u(&gb) << 8;
251 dst32[1] = bytestream2_get_be24u(&gb) << 8;
252 dst32[2] = bytestream2_get_be24u(&gb) << 8;
253 dst32[5] = bytestream2_get_be24u(&gb) << 8;
254 dst32[3] = bytestream2_get_be24u(&gb) << 8;
255 dst32[4] = bytestream2_get_be24u(&gb) << 8;
256 dst32[6] = bytestream2_get_be24u(&gb) << 8;
258 bytestream2_skip(&gb, 3);
262 /* remapping: L, R, C, LSide, LBack, RBack, RSide, LF */
263 case AV_CH_LAYOUT_7POINT1:
264 if (AV_SAMPLE_FMT_S16 == avctx->sample_fmt) {
266 dst16[0] = bytestream2_get_be16u(&gb);
267 dst16[1] = bytestream2_get_be16u(&gb);
268 dst16[2] = bytestream2_get_be16u(&gb);
269 dst16[6] = bytestream2_get_be16u(&gb);
270 dst16[4] = bytestream2_get_be16u(&gb);
271 dst16[5] = bytestream2_get_be16u(&gb);
272 dst16[7] = bytestream2_get_be16u(&gb);
273 dst16[3] = bytestream2_get_be16u(&gb);
278 dst32[0] = bytestream2_get_be24u(&gb) << 8;
279 dst32[1] = bytestream2_get_be24u(&gb) << 8;
280 dst32[2] = bytestream2_get_be24u(&gb) << 8;
281 dst32[6] = bytestream2_get_be24u(&gb) << 8;
282 dst32[4] = bytestream2_get_be24u(&gb) << 8;
283 dst32[5] = bytestream2_get_be24u(&gb) << 8;
284 dst32[7] = bytestream2_get_be24u(&gb) << 8;
285 dst32[3] = bytestream2_get_be24u(&gb) << 8;
295 retval = bytestream2_tell(&gb);
296 if (avctx->debug & FF_DEBUG_BITSTREAM)
297 av_dlog(avctx, "pcm_bluray_decode_frame: decoded %d -> %d bytes\n",
302 AVCodec ff_pcm_bluray_decoder = {
303 .name = "pcm_bluray",
304 .type = AVMEDIA_TYPE_AUDIO,
305 .id = AV_CODEC_ID_PCM_BLURAY,
306 .decode = pcm_bluray_decode_frame,
307 .capabilities = CODEC_CAP_DR1,
308 .sample_fmts = (const enum AVSampleFormat[]){
309 AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_S32, AV_SAMPLE_FMT_NONE
311 .long_name = NULL_IF_CONFIG_SMALL("PCM signed 16|20|24-bit big-endian for Blu-ray media"),