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/channel_layout.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
, "reserved sample depth (0)\n");
76 avctx
->sample_fmt
= avctx
->bits_per_coded_sample
== 16 ? AV_SAMPLE_FMT_S16
:
78 avctx
->bits_per_raw_sample
= avctx
->bits_per_coded_sample
;
80 /* get the sample rate. Not all values are used. */
81 switch (header
[2] & 0x0f) {
83 avctx
->sample_rate
= 48000;
86 avctx
->sample_rate
= 96000;
89 avctx
->sample_rate
= 192000;
92 avctx
->sample_rate
= 0;
93 av_log(avctx
, AV_LOG_ERROR
, "reserved sample rate (%d)\n",
99 * get the channel number (and mapping). Not all values are used.
100 * It must be noted that the number of channels in the MPEG stream can
101 * differ from the actual meaningful number, e.g. mono audio still has two
102 * channels, one being empty.
104 avctx
->channel_layout
= channel_layouts
[channel_layout
];
105 avctx
->channels
= channels
[channel_layout
];
106 if (!avctx
->channels
) {
107 av_log(avctx
, AV_LOG_ERROR
, "reserved channel configuration (%d)\n",
112 avctx
->bit_rate
= FFALIGN(avctx
->channels
, 2) * avctx
->sample_rate
*
113 avctx
->bits_per_coded_sample
;
115 if (avctx
->debug
& FF_DEBUG_PICT_INFO
)
117 "pcm_bluray_parse_header: %d channels, %d bits per sample, %d Hz, %d bit/s\n",
118 avctx
->channels
, avctx
->bits_per_coded_sample
,
119 avctx
->sample_rate
, avctx
->bit_rate
);
123 typedef struct PCMBRDecode
{
127 static av_cold
int pcm_bluray_decode_init(AVCodecContext
* avctx
)
129 PCMBRDecode
*s
= avctx
->priv_data
;
131 avcodec_get_frame_defaults(&s
->frame
);
132 avctx
->coded_frame
= &s
->frame
;
137 static int pcm_bluray_decode_frame(AVCodecContext
*avctx
, void *data
,
138 int *got_frame_ptr
, AVPacket
*avpkt
)
140 const uint8_t *src
= avpkt
->data
;
141 int buf_size
= avpkt
->size
;
142 PCMBRDecode
*s
= avctx
->priv_data
;
144 int num_source_channels
, channel
, retval
;
145 int sample_size
, samples
;
150 av_log(avctx
, AV_LOG_ERROR
, "PCM packet too small\n");
154 if (pcm_bluray_parse_header(avctx
, src
))
159 bytestream2_init(&gb
, src
, buf_size
);
161 /* There's always an even number of channels in the source */
162 num_source_channels
= FFALIGN(avctx
->channels
, 2);
163 sample_size
= (num_source_channels
* (avctx
->sample_fmt
== AV_SAMPLE_FMT_S16 ?
16 : 24)) >> 3;
164 samples
= buf_size
/ sample_size
;
166 /* get output buffer */
167 s
->frame
.nb_samples
= samples
;
168 if ((retval
= avctx
->get_buffer(avctx
, &s
->frame
)) < 0) {
169 av_log(avctx
, AV_LOG_ERROR
, "get_buffer() failed\n");
172 dst16
= (int16_t *)s
->frame
.data
[0];
173 dst32
= (int32_t *)s
->frame
.data
[0];
176 switch (avctx
->channel_layout
) {
177 /* cases with same number of source and coded channels */
178 case AV_CH_LAYOUT_STEREO
:
179 case AV_CH_LAYOUT_4POINT0
:
180 case AV_CH_LAYOUT_2_2
:
181 samples
*= num_source_channels
;
182 if (AV_SAMPLE_FMT_S16
== avctx
->sample_fmt
) {
184 bytestream2_get_buffer(&gb
, dst16
, buf_size
);
187 *dst16
++ = bytestream2_get_be16u(&gb
);
192 *dst32
++ = bytestream2_get_be24u(&gb
) << 8;
196 /* cases where number of source channels = coded channels + 1 */
197 case AV_CH_LAYOUT_MONO
:
198 case AV_CH_LAYOUT_SURROUND
:
199 case AV_CH_LAYOUT_2_1
:
200 case AV_CH_LAYOUT_5POINT0
:
201 if (AV_SAMPLE_FMT_S16
== avctx
->sample_fmt
) {
204 bytestream2_get_buffer(&gb
, dst16
, avctx
->channels
* 2);
205 dst16
+= avctx
->channels
;
207 channel
= avctx
->channels
;
209 *dst16
++ = bytestream2_get_be16u(&gb
);
212 bytestream2_skip(&gb
, 2);
216 channel
= avctx
->channels
;
218 *dst32
++ = bytestream2_get_be24u(&gb
) << 8;
220 bytestream2_skip(&gb
, 3);
224 /* remapping: L, R, C, LBack, RBack, LF */
225 case AV_CH_LAYOUT_5POINT1
:
226 if (AV_SAMPLE_FMT_S16
== avctx
->sample_fmt
) {
228 dst16
[0] = bytestream2_get_be16u(&gb
);
229 dst16
[1] = bytestream2_get_be16u(&gb
);
230 dst16
[2] = bytestream2_get_be16u(&gb
);
231 dst16
[4] = bytestream2_get_be16u(&gb
);
232 dst16
[5] = bytestream2_get_be16u(&gb
);
233 dst16
[3] = bytestream2_get_be16u(&gb
);
238 dst32
[0] = bytestream2_get_be24u(&gb
) << 8;
239 dst32
[1] = bytestream2_get_be24u(&gb
) << 8;
240 dst32
[2] = bytestream2_get_be24u(&gb
) << 8;
241 dst32
[4] = bytestream2_get_be24u(&gb
) << 8;
242 dst32
[5] = bytestream2_get_be24u(&gb
) << 8;
243 dst32
[3] = bytestream2_get_be24u(&gb
) << 8;
248 /* remapping: L, R, C, LSide, LBack, RBack, RSide, <unused> */
249 case AV_CH_LAYOUT_7POINT0
:
250 if (AV_SAMPLE_FMT_S16
== avctx
->sample_fmt
) {
252 dst16
[0] = bytestream2_get_be16u(&gb
);
253 dst16
[1] = bytestream2_get_be16u(&gb
);
254 dst16
[2] = bytestream2_get_be16u(&gb
);
255 dst16
[5] = bytestream2_get_be16u(&gb
);
256 dst16
[3] = bytestream2_get_be16u(&gb
);
257 dst16
[4] = bytestream2_get_be16u(&gb
);
258 dst16
[6] = bytestream2_get_be16u(&gb
);
260 bytestream2_skip(&gb
, 2);
264 dst32
[0] = bytestream2_get_be24u(&gb
) << 8;
265 dst32
[1] = bytestream2_get_be24u(&gb
) << 8;
266 dst32
[2] = bytestream2_get_be24u(&gb
) << 8;
267 dst32
[5] = bytestream2_get_be24u(&gb
) << 8;
268 dst32
[3] = bytestream2_get_be24u(&gb
) << 8;
269 dst32
[4] = bytestream2_get_be24u(&gb
) << 8;
270 dst32
[6] = bytestream2_get_be24u(&gb
) << 8;
272 bytestream2_skip(&gb
, 3);
276 /* remapping: L, R, C, LSide, LBack, RBack, RSide, LF */
277 case AV_CH_LAYOUT_7POINT1
:
278 if (AV_SAMPLE_FMT_S16
== avctx
->sample_fmt
) {
280 dst16
[0] = bytestream2_get_be16u(&gb
);
281 dst16
[1] = bytestream2_get_be16u(&gb
);
282 dst16
[2] = bytestream2_get_be16u(&gb
);
283 dst16
[6] = bytestream2_get_be16u(&gb
);
284 dst16
[4] = bytestream2_get_be16u(&gb
);
285 dst16
[5] = bytestream2_get_be16u(&gb
);
286 dst16
[7] = bytestream2_get_be16u(&gb
);
287 dst16
[3] = bytestream2_get_be16u(&gb
);
292 dst32
[0] = bytestream2_get_be24u(&gb
) << 8;
293 dst32
[1] = bytestream2_get_be24u(&gb
) << 8;
294 dst32
[2] = bytestream2_get_be24u(&gb
) << 8;
295 dst32
[6] = bytestream2_get_be24u(&gb
) << 8;
296 dst32
[4] = bytestream2_get_be24u(&gb
) << 8;
297 dst32
[5] = bytestream2_get_be24u(&gb
) << 8;
298 dst32
[7] = bytestream2_get_be24u(&gb
) << 8;
299 dst32
[3] = bytestream2_get_be24u(&gb
) << 8;
308 *(AVFrame
*)data
= s
->frame
;
310 retval
= bytestream2_tell(&gb
);
311 if (avctx
->debug
& FF_DEBUG_BITSTREAM
)
312 av_dlog(avctx
, "pcm_bluray_decode_frame: decoded %d -> %d bytes\n",
317 AVCodec ff_pcm_bluray_decoder
= {
318 .name
= "pcm_bluray",
319 .type
= AVMEDIA_TYPE_AUDIO
,
320 .id
= AV_CODEC_ID_PCM_BLURAY
,
321 .priv_data_size
= sizeof(PCMBRDecode
),
322 .init
= pcm_bluray_decode_init
,
323 .decode
= pcm_bluray_decode_frame
,
324 .capabilities
= CODEC_CAP_DR1
,
325 .sample_fmts
= (const enum AVSampleFormat
[]){
326 AV_SAMPLE_FMT_S16
, AV_SAMPLE_FMT_S32
, AV_SAMPLE_FMT_NONE
328 .long_name
= NULL_IF_CONFIG_SMALL("PCM signed 16|20|24-bit big-endian for Blu-ray media"),