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2ba45a60 DM |
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 20/24bit 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_dlog(avctx, "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 20/24bit 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 | av_dlog(avctx, | |
143 | "pcm_dvd_parse_header: %d channels, %d bits per sample, %d Hz, %d bit/s\n", | |
144 | avctx->channels, avctx->bits_per_coded_sample, | |
145 | avctx->sample_rate, 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; | |
2ba45a60 DM |
161 | |
162 | bytestream2_init(&gb, src, blocks * s->block_size); | |
163 | switch (avctx->bits_per_coded_sample) { | |
f6fa7814 | 164 | case 16: { |
2ba45a60 DM |
165 | #if HAVE_BIGENDIAN |
166 | bytestream2_get_buffer(&gb, dst16, blocks * s->block_size); | |
167 | dst16 += blocks * s->block_size / 2; | |
168 | #else | |
f6fa7814 | 169 | int samples = blocks * avctx->channels; |
2ba45a60 DM |
170 | do { |
171 | *dst16++ = bytestream2_get_be16u(&gb); | |
172 | } while (--samples); | |
173 | #endif | |
174 | return dst16; | |
f6fa7814 | 175 | } |
2ba45a60 DM |
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 = CODEC_CAP_DR1, | |
315 | .sample_fmts = (const enum AVSampleFormat[]) { | |
316 | AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_S32, AV_SAMPLE_FMT_NONE | |
317 | } | |
318 | }; |