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pcm-dvd.c
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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
40 
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 
55 {
56  PCMDVDContext *s = avctx->priv_data;
57 
59 
60  return 0;
61 }
62 
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
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, 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 
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),
313  .close = pcm_dvd_decode_uninit,
314  .capabilities = AV_CODEC_CAP_DR1,
315  .sample_fmts = (const enum AVSampleFormat[]) {
317  }
318 };
#define NULL
Definition: coverity.c:32
const char * s
Definition: avisynth_c.h:768
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
This structure describes decoded (raw) audio or video data.
Definition: frame.h:201
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:101
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
int64_t bit_rate
the average bitrate
Definition: avcodec.h:1538
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
int size
Definition: avcodec.h:1401
static av_cold int pcm_dvd_decode_uninit(AVCodecContext *avctx)
Definition: pcm-dvd.c:54
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:133
int bits_per_raw_sample
Bits per sample/pixel of internal libavcodec pixel/sample format.
Definition: avcodec.h:2711
#define src
Definition: vp8dsp.c:254
AVCodec.
Definition: avcodec.h:3351
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:42
enum AVSampleFormat sample_fmt
audio sample format
Definition: avcodec.h:2151
uint8_t
#define av_cold
Definition: attributes.h:82
#define av_malloc(s)
#define FF_DEBUG_PICT_INFO
Definition: avcodec.h:2569
static AVFrame * frame
uint8_t * data
Definition: avcodec.h:1400
#define ff_dlog(a,...)
static const uint8_t header[24]
Definition: sdr2.c:67
int bits_per_coded_sample
bits per sample/pixel from the demuxer (needed for huffyuv).
Definition: avcodec.h:2704
signed 32 bits
Definition: samplefmt.h:62
static void * pcm_dvd_decode_samples(AVCodecContext *avctx, const uint8_t *src, void *dst, int blocks)
Definition: pcm-dvd.c:152
#define av_log(a,...)
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
int groups_per_block
Definition: pcm-dvd.c:36
#define AVERROR(e)
Definition: error.h:43
static int pcm_dvd_decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt)
Definition: pcm-dvd.c:234
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
static av_always_inline unsigned int bytestream2_get_buffer(GetByteContext *g, uint8_t *dst, unsigned int size)
Definition: bytestream.h:263
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:197
const char * name
Name of the codec implementation.
Definition: avcodec.h:3358
int samples_per_block
Definition: pcm-dvd.c:35
int last_block_size
Definition: pcm-dvd.c:34
int extra_sample_count
Definition: pcm-dvd.c:38
int32_t
Libavcodec external API header.
uint32_t last_header
Definition: pcm-dvd.c:32
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:58
int sample_rate
samples per second
Definition: avcodec.h:2143
int debug
debug
Definition: avcodec.h:2568
main external API structure.
Definition: avcodec.h:1488
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1886
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:215
static av_cold int pcm_dvd_decode_init(AVCodecContext *avctx)
Definition: pcm-dvd.c:41
common internal api header.
if(ret< 0)
Definition: vf_mcdeint.c:279
signed 16 bits
Definition: samplefmt.h:61
void * priv_data
Definition: avcodec.h:1515
int channels
number of audio channels
Definition: avcodec.h:2144
static enum AVSampleFormat sample_fmts[]
Definition: adpcmenc.c:701
#define av_freep(p)
int block_size
Definition: pcm-dvd.c:33
uint8_t * extra_samples
Definition: pcm-dvd.c:37
This structure stores compressed data.
Definition: avcodec.h:1377
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:267
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:956
static int pcm_dvd_parse_header(AVCodecContext *avctx, const uint8_t *header)
Definition: pcm-dvd.c:63
AVCodec ff_pcm_dvd_decoder
Definition: pcm-dvd.c:305