blob: 04c321e677e6f02490df2bfd8817dc75415817dd
1 | /* |
2 | * LPCM codecs for PCM formats found in Video DVD streams |
3 | * Copyright (c) 2013 Christian Schmidt |
4 | * |
5 | * This file is part of FFmpeg. |
6 | * |
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. |
11 | * |
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. |
16 | * |
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 |
20 | */ |
21 | |
22 | /** |
23 | * @file |
24 | * LPCM codecs for PCM formats found in Video DVD streams |
25 | */ |
26 | |
27 | #include "avcodec.h" |
28 | #include "bytestream.h" |
29 | #include "internal.h" |
30 | |
31 | typedef struct PCMDVDContext { |
32 | uint32_t last_header; // Cached header to see if parsing is needed |
33 | int block_size; // Size of a block of samples in bytes |
34 | int last_block_size; // Size of the last block of samples in bytes |
35 | int samples_per_block; // Number of samples per channel per block |
36 | int groups_per_block; // Number of 20/24-bit sample groups per block |
37 | uint8_t *extra_samples; // Pointer to leftover samples from a frame |
38 | int extra_sample_count; // Number of leftover samples in the buffer |
39 | } PCMDVDContext; |
40 | |
41 | static av_cold int pcm_dvd_decode_init(AVCodecContext *avctx) |
42 | { |
43 | PCMDVDContext *s = avctx->priv_data; |
44 | |
45 | /* Invalid header to force parsing of the first header */ |
46 | s->last_header = -1; |
47 | /* reserve space for 8 channels, 3 bytes/sample, 4 samples/block */ |
48 | if (!(s->extra_samples = av_malloc(8 * 3 * 4))) |
49 | return AVERROR(ENOMEM); |
50 | |
51 | return 0; |
52 | } |
53 | |
54 | static av_cold int pcm_dvd_decode_uninit(AVCodecContext *avctx) |
55 | { |
56 | PCMDVDContext *s = avctx->priv_data; |
57 | |
58 | av_freep(&s->extra_samples); |
59 | |
60 | return 0; |
61 | } |
62 | |
63 | static int pcm_dvd_parse_header(AVCodecContext *avctx, const uint8_t *header) |
64 | { |
65 | /* no traces of 44100 and 32000Hz in any commercial software or player */ |
66 | static const uint32_t frequencies[4] = { 48000, 96000, 44100, 32000 }; |
67 | PCMDVDContext *s = avctx->priv_data; |
68 | int header_int = (header[0] & 0xe0) | (header[1] << 8) | (header[2] << 16); |
69 | |
70 | /* early exit if the header didn't change apart from the frame number */ |
71 | if (s->last_header == header_int) |
72 | return 0; |
73 | s->last_header = -1; |
74 | |
75 | if (avctx->debug & FF_DEBUG_PICT_INFO) |
76 | av_log(avctx, AV_LOG_DEBUG, "pcm_dvd_parse_header: header = %02x%02x%02x\n", |
77 | header[0], header[1], header[2]); |
78 | /* |
79 | * header[0] emphasis (1), muse(1), reserved(1), frame number(5) |
80 | * header[1] quant (2), freq(2), reserved(1), channels(3) |
81 | * header[2] dynamic range control (0x80 = off) |
82 | */ |
83 | |
84 | /* Discard potentially existing leftover samples from old channel layout */ |
85 | s->extra_sample_count = 0; |
86 | |
87 | /* get the sample depth and derive the sample format from it */ |
88 | avctx->bits_per_coded_sample = 16 + (header[1] >> 6 & 3) * 4; |
89 | if (avctx->bits_per_coded_sample == 28) { |
90 | av_log(avctx, AV_LOG_ERROR, |
91 | "PCM DVD unsupported sample depth %i\n", |
92 | avctx->bits_per_coded_sample); |
93 | return AVERROR_INVALIDDATA; |
94 | } |
95 | avctx->sample_fmt = avctx->bits_per_coded_sample == 16 ? AV_SAMPLE_FMT_S16 |
96 | : AV_SAMPLE_FMT_S32; |
97 | avctx->bits_per_raw_sample = avctx->bits_per_coded_sample; |
98 | |
99 | /* get the sample rate */ |
100 | avctx->sample_rate = frequencies[header[1] >> 4 & 3]; |
101 | |
102 | /* get the number of channels */ |
103 | avctx->channels = 1 + (header[1] & 7); |
104 | /* calculate the bitrate */ |
105 | avctx->bit_rate = avctx->channels * |
106 | avctx->sample_rate * |
107 | avctx->bits_per_coded_sample; |
108 | |
109 | /* 4 samples form a group in 20/24-bit PCM on DVD Video. |
110 | * A block is formed by the number of groups that are |
111 | * needed to complete a set of samples for each channel. */ |
112 | if (avctx->bits_per_coded_sample == 16) { |
113 | s->samples_per_block = 1; |
114 | s->block_size = avctx->channels * 2; |
115 | } else { |
116 | switch (avctx->channels) { |
117 | case 1: |
118 | case 2: |
119 | case 4: |
120 | /* one group has all the samples needed */ |
121 | s->block_size = 4 * avctx->bits_per_coded_sample / 8; |
122 | s->samples_per_block = 4 / avctx->channels; |
123 | s->groups_per_block = 1; |
124 | break; |
125 | case 8: |
126 | /* two groups have all the samples needed */ |
127 | s->block_size = 8 * avctx->bits_per_coded_sample / 8; |
128 | s->samples_per_block = 1; |
129 | s->groups_per_block = 2; |
130 | break; |
131 | default: |
132 | /* need avctx->channels groups */ |
133 | s->block_size = 4 * avctx->channels * |
134 | avctx->bits_per_coded_sample / 8; |
135 | s->samples_per_block = 4; |
136 | s->groups_per_block = avctx->channels; |
137 | break; |
138 | } |
139 | } |
140 | |
141 | if (avctx->debug & FF_DEBUG_PICT_INFO) |
142 | ff_dlog(avctx, |
143 | "pcm_dvd_parse_header: %d channels, %d bits per sample, %d Hz, %"PRId64" bit/s\n", |
144 | avctx->channels, avctx->bits_per_coded_sample, |
145 | avctx->sample_rate, (int64_t)avctx->bit_rate); |
146 | |
147 | s->last_header = header_int; |
148 | |
149 | return 0; |
150 | } |
151 | |
152 | static void *pcm_dvd_decode_samples(AVCodecContext *avctx, const uint8_t *src, |
153 | void *dst, int blocks) |
154 | { |
155 | PCMDVDContext *s = avctx->priv_data; |
156 | int16_t *dst16 = dst; |
157 | int32_t *dst32 = dst; |
158 | GetByteContext gb; |
159 | int i; |
160 | uint8_t t; |
161 | |
162 | bytestream2_init(&gb, src, blocks * s->block_size); |
163 | switch (avctx->bits_per_coded_sample) { |
164 | case 16: { |
165 | #if HAVE_BIGENDIAN |
166 | bytestream2_get_buffer(&gb, dst16, blocks * s->block_size); |
167 | dst16 += blocks * s->block_size / 2; |
168 | #else |
169 | int samples = blocks * avctx->channels; |
170 | do { |
171 | *dst16++ = bytestream2_get_be16u(&gb); |
172 | } while (--samples); |
173 | #endif |
174 | return dst16; |
175 | } |
176 | case 20: |
177 | if (avctx->channels == 1) { |
178 | do { |
179 | for (i = 2; i; i--) { |
180 | dst32[0] = bytestream2_get_be16u(&gb) << 16; |
181 | dst32[1] = bytestream2_get_be16u(&gb) << 16; |
182 | t = bytestream2_get_byteu(&gb); |
183 | *dst32++ += (t & 0xf0) << 8; |
184 | *dst32++ += (t & 0x0f) << 12; |
185 | } |
186 | } while (--blocks); |
187 | } else { |
188 | do { |
189 | for (i = s->groups_per_block; i; i--) { |
190 | dst32[0] = bytestream2_get_be16u(&gb) << 16; |
191 | dst32[1] = bytestream2_get_be16u(&gb) << 16; |
192 | dst32[2] = bytestream2_get_be16u(&gb) << 16; |
193 | dst32[3] = bytestream2_get_be16u(&gb) << 16; |
194 | t = bytestream2_get_byteu(&gb); |
195 | *dst32++ += (t & 0xf0) << 8; |
196 | *dst32++ += (t & 0x0f) << 12; |
197 | t = bytestream2_get_byteu(&gb); |
198 | *dst32++ += (t & 0xf0) << 8; |
199 | *dst32++ += (t & 0x0f) << 12; |
200 | } |
201 | } while (--blocks); |
202 | } |
203 | return dst32; |
204 | case 24: |
205 | if (avctx->channels == 1) { |
206 | do { |
207 | for (i = 2; i; i--) { |
208 | dst32[0] = bytestream2_get_be16u(&gb) << 16; |
209 | dst32[1] = bytestream2_get_be16u(&gb) << 16; |
210 | *dst32++ += bytestream2_get_byteu(&gb) << 8; |
211 | *dst32++ += bytestream2_get_byteu(&gb) << 8; |
212 | } |
213 | } while (--blocks); |
214 | } else { |
215 | do { |
216 | for (i = s->groups_per_block; i; i--) { |
217 | dst32[0] = bytestream2_get_be16u(&gb) << 16; |
218 | dst32[1] = bytestream2_get_be16u(&gb) << 16; |
219 | dst32[2] = bytestream2_get_be16u(&gb) << 16; |
220 | dst32[3] = bytestream2_get_be16u(&gb) << 16; |
221 | *dst32++ += bytestream2_get_byteu(&gb) << 8; |
222 | *dst32++ += bytestream2_get_byteu(&gb) << 8; |
223 | *dst32++ += bytestream2_get_byteu(&gb) << 8; |
224 | *dst32++ += bytestream2_get_byteu(&gb) << 8; |
225 | } |
226 | } while (--blocks); |
227 | } |
228 | return dst32; |
229 | default: |
230 | return NULL; |
231 | } |
232 | } |
233 | |
234 | static int pcm_dvd_decode_frame(AVCodecContext *avctx, void *data, |
235 | int *got_frame_ptr, AVPacket *avpkt) |
236 | { |
237 | AVFrame *frame = data; |
238 | const uint8_t *src = avpkt->data; |
239 | int buf_size = avpkt->size; |
240 | PCMDVDContext *s = avctx->priv_data; |
241 | int retval; |
242 | int blocks; |
243 | void *dst; |
244 | |
245 | if (buf_size < 3) { |
246 | av_log(avctx, AV_LOG_ERROR, "PCM packet too small\n"); |
247 | return AVERROR_INVALIDDATA; |
248 | } |
249 | |
250 | if ((retval = pcm_dvd_parse_header(avctx, src))) |
251 | return retval; |
252 | if (s->last_block_size && s->last_block_size != s->block_size) { |
253 | av_log(avctx, AV_LOG_WARNING, "block_size has changed %d != %d\n", s->last_block_size, s->block_size); |
254 | s->extra_sample_count = 0; |
255 | } |
256 | s->last_block_size = s->block_size; |
257 | src += 3; |
258 | buf_size -= 3; |
259 | |
260 | blocks = (buf_size + s->extra_sample_count) / s->block_size; |
261 | |
262 | /* get output buffer */ |
263 | frame->nb_samples = blocks * s->samples_per_block; |
264 | if ((retval = ff_get_buffer(avctx, frame, 0)) < 0) |
265 | return retval; |
266 | dst = frame->data[0]; |
267 | |
268 | /* consume leftover samples from last packet */ |
269 | if (s->extra_sample_count) { |
270 | int missing_samples = s->block_size - s->extra_sample_count; |
271 | if (buf_size >= missing_samples) { |
272 | memcpy(s->extra_samples + s->extra_sample_count, src, |
273 | missing_samples); |
274 | dst = pcm_dvd_decode_samples(avctx, s->extra_samples, dst, 1); |
275 | src += missing_samples; |
276 | buf_size -= missing_samples; |
277 | s->extra_sample_count = 0; |
278 | blocks--; |
279 | } else { |
280 | /* new packet still doesn't have enough samples */ |
281 | memcpy(s->extra_samples + s->extra_sample_count, src, buf_size); |
282 | s->extra_sample_count += buf_size; |
283 | return avpkt->size; |
284 | } |
285 | } |
286 | |
287 | /* decode remaining complete samples */ |
288 | if (blocks) { |
289 | pcm_dvd_decode_samples(avctx, src, dst, blocks); |
290 | buf_size -= blocks * s->block_size; |
291 | } |
292 | |
293 | /* store leftover samples */ |
294 | if (buf_size) { |
295 | src += blocks * s->block_size; |
296 | memcpy(s->extra_samples, src, buf_size); |
297 | s->extra_sample_count = buf_size; |
298 | } |
299 | |
300 | *got_frame_ptr = 1; |
301 | |
302 | return avpkt->size; |
303 | } |
304 | |
305 | AVCodec ff_pcm_dvd_decoder = { |
306 | .name = "pcm_dvd", |
307 | .long_name = NULL_IF_CONFIG_SMALL("PCM signed 16|20|24-bit big-endian for DVD media"), |
308 | .type = AVMEDIA_TYPE_AUDIO, |
309 | .id = AV_CODEC_ID_PCM_DVD, |
310 | .priv_data_size = sizeof(PCMDVDContext), |
311 | .init = pcm_dvd_decode_init, |
312 | .decode = pcm_dvd_decode_frame, |
313 | .close = pcm_dvd_decode_uninit, |
314 | .capabilities = AV_CODEC_CAP_DR1, |
315 | .sample_fmts = (const enum AVSampleFormat[]) { |
316 | AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_S32, AV_SAMPLE_FMT_NONE |
317 | } |
318 | }; |
319 |