FFmpeg
truespeech.c
Go to the documentation of this file.
1 /*
2  * DSP Group TrueSpeech compatible decoder
3  * Copyright (c) 2005 Konstantin Shishkov
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 
23 #include "libavutil/intreadwrite.h"
24 #include "libavutil/mem_internal.h"
25 
26 #include "avcodec.h"
27 #include "bswapdsp.h"
28 #include "get_bits.h"
29 #include "internal.h"
30 
31 #include "truespeech_data.h"
32 /**
33  * @file
34  * TrueSpeech decoder.
35  */
36 
37 /**
38  * TrueSpeech decoder context
39  */
40 typedef struct TSContext {
42  /* input data */
43  DECLARE_ALIGNED(16, uint8_t, buffer)[32];
44  int16_t vector[8]; ///< input vector: 5/5/4/4/4/3/3/3
45  int offset1[2]; ///< 8-bit value, used in one copying offset
46  int offset2[4]; ///< 7-bit value, encodes offsets for copying and for two-point filter
47  int pulseoff[4]; ///< 4-bit offset of pulse values block
48  int pulsepos[4]; ///< 27-bit variable, encodes 7 pulse positions
49  int pulseval[4]; ///< 7x2-bit pulse values
50  int flag; ///< 1-bit flag, shows how to choose filters
51  /* temporary data */
52  int filtbuf[146]; // some big vector used for storing filters
53  int prevfilt[8]; // filter from previous frame
54  int16_t tmp1[8]; // coefficients for adding to out
55  int16_t tmp2[8]; // coefficients for adding to out
56  int16_t tmp3[8]; // coefficients for adding to out
57  int16_t cvector[8]; // correlated input vector
58  int filtval; // gain value for one function
59  int16_t newvec[60]; // tmp vector
60  int16_t filters[32]; // filters for every subframe
61 } TSContext;
62 
64 {
65  TSContext *c = avctx->priv_data;
66 
67  if (avctx->channels != 1) {
68  avpriv_request_sample(avctx, "Channel count %d", avctx->channels);
69  return AVERROR_PATCHWELCOME;
70  }
71 
74 
75  ff_bswapdsp_init(&c->bdsp);
76 
77  return 0;
78 }
79 
80 static void truespeech_read_frame(TSContext *dec, const uint8_t *input)
81 {
82  GetBitContext gb;
83 
84  dec->bdsp.bswap_buf((uint32_t *) dec->buffer, (const uint32_t *) input, 8);
85  init_get_bits(&gb, dec->buffer, 32 * 8);
86 
87  dec->vector[7] = ts_codebook[7][get_bits(&gb, 3)];
88  dec->vector[6] = ts_codebook[6][get_bits(&gb, 3)];
89  dec->vector[5] = ts_codebook[5][get_bits(&gb, 3)];
90  dec->vector[4] = ts_codebook[4][get_bits(&gb, 4)];
91  dec->vector[3] = ts_codebook[3][get_bits(&gb, 4)];
92  dec->vector[2] = ts_codebook[2][get_bits(&gb, 4)];
93  dec->vector[1] = ts_codebook[1][get_bits(&gb, 5)];
94  dec->vector[0] = ts_codebook[0][get_bits(&gb, 5)];
95  dec->flag = get_bits1(&gb);
96 
97  dec->offset1[0] = get_bits(&gb, 4) << 4;
98  dec->offset2[3] = get_bits(&gb, 7);
99  dec->offset2[2] = get_bits(&gb, 7);
100  dec->offset2[1] = get_bits(&gb, 7);
101  dec->offset2[0] = get_bits(&gb, 7);
102 
103  dec->offset1[1] = get_bits(&gb, 4);
104  dec->pulseval[1] = get_bits(&gb, 14);
105  dec->pulseval[0] = get_bits(&gb, 14);
106 
107  dec->offset1[1] |= get_bits(&gb, 4) << 4;
108  dec->pulseval[3] = get_bits(&gb, 14);
109  dec->pulseval[2] = get_bits(&gb, 14);
110 
111  dec->offset1[0] |= get_bits1(&gb);
112  dec->pulsepos[0] = get_bits_long(&gb, 27);
113  dec->pulseoff[0] = get_bits(&gb, 4);
114 
115  dec->offset1[0] |= get_bits1(&gb) << 1;
116  dec->pulsepos[1] = get_bits_long(&gb, 27);
117  dec->pulseoff[1] = get_bits(&gb, 4);
118 
119  dec->offset1[0] |= get_bits1(&gb) << 2;
120  dec->pulsepos[2] = get_bits_long(&gb, 27);
121  dec->pulseoff[2] = get_bits(&gb, 4);
122 
123  dec->offset1[0] |= get_bits1(&gb) << 3;
124  dec->pulsepos[3] = get_bits_long(&gb, 27);
125  dec->pulseoff[3] = get_bits(&gb, 4);
126 }
127 
129 {
130  int16_t tmp[8];
131  int i, j;
132 
133  for(i = 0; i < 8; i++){
134  if(i > 0){
135  memcpy(tmp, dec->cvector, i * sizeof(*tmp));
136  for(j = 0; j < i; j++)
137  dec->cvector[j] += (tmp[i - j - 1] * dec->vector[i] + 0x4000) >> 15;
138  }
139  dec->cvector[i] = (8 - dec->vector[i]) >> 3;
140  }
141  for(i = 0; i < 8; i++)
142  dec->cvector[i] = (dec->cvector[i] * ts_decay_994_1000[i]) >> 15;
143 
144  dec->filtval = dec->vector[0];
145 }
146 
148 {
149  int i;
150 
151  if(!dec->flag){
152  for(i = 0; i < 8; i++){
153  dec->filters[i + 0] = dec->prevfilt[i];
154  dec->filters[i + 8] = dec->prevfilt[i];
155  }
156  }else{
157  for(i = 0; i < 8; i++){
158  dec->filters[i + 0]=(dec->cvector[i] * 21846 + dec->prevfilt[i] * 10923 + 16384) >> 15;
159  dec->filters[i + 8]=(dec->cvector[i] * 10923 + dec->prevfilt[i] * 21846 + 16384) >> 15;
160  }
161  }
162  for(i = 0; i < 8; i++){
163  dec->filters[i + 16] = dec->cvector[i];
164  dec->filters[i + 24] = dec->cvector[i];
165  }
166 }
167 
168 static void truespeech_apply_twopoint_filter(TSContext *dec, int quart)
169 {
170  int16_t tmp[146 + 60], *ptr0, *ptr1;
171  const int16_t *filter;
172  int i, t, off;
173 
174  t = dec->offset2[quart];
175  if(t == 127){
176  memset(dec->newvec, 0, 60 * sizeof(*dec->newvec));
177  return;
178  }
179  for(i = 0; i < 146; i++)
180  tmp[i] = dec->filtbuf[i];
181  off = (t / 25) + dec->offset1[quart >> 1] + 18;
182  off = av_clip(off, 0, 145);
183  ptr0 = tmp + 145 - off;
184  ptr1 = tmp + 146;
185  filter = ts_order2_coeffs + (t % 25) * 2;
186  for(i = 0; i < 60; i++){
187  t = (ptr0[0] * filter[0] + ptr0[1] * filter[1] + 0x2000) >> 14;
188  ptr0++;
189  dec->newvec[i] = t;
190  ptr1[i] = t;
191  }
192 }
193 
194 static void truespeech_place_pulses(TSContext *dec, int16_t *out, int quart)
195 {
196  int16_t tmp[7];
197  int i, j, t;
198  const int16_t *ptr1;
199  int16_t *ptr2;
200  int coef;
201 
202  memset(out, 0, 60 * sizeof(*out));
203  for(i = 0; i < 7; i++) {
204  t = dec->pulseval[quart] & 3;
205  dec->pulseval[quart] >>= 2;
206  tmp[6 - i] = ts_pulse_scales[dec->pulseoff[quart] * 4 + t];
207  }
208 
209  coef = dec->pulsepos[quart] >> 15;
210  ptr1 = ts_pulse_values + 30;
211  ptr2 = tmp;
212  for(i = 0, j = 3; (i < 30) && (j > 0); i++){
213  t = *ptr1++;
214  if(coef >= t)
215  coef -= t;
216  else{
217  out[i] = *ptr2++;
218  ptr1 += 30;
219  j--;
220  }
221  }
222  coef = dec->pulsepos[quart] & 0x7FFF;
223  ptr1 = ts_pulse_values;
224  for(i = 30, j = 4; (i < 60) && (j > 0); i++){
225  t = *ptr1++;
226  if(coef >= t)
227  coef -= t;
228  else{
229  out[i] = *ptr2++;
230  ptr1 += 30;
231  j--;
232  }
233  }
234 
235 }
236 
237 static void truespeech_update_filters(TSContext *dec, int16_t *out, int quart)
238 {
239  int i;
240 
241  memmove(dec->filtbuf, &dec->filtbuf[60], 86 * sizeof(*dec->filtbuf));
242  for(i = 0; i < 60; i++){
243  dec->filtbuf[i + 86] = out[i] + dec->newvec[i] - (dec->newvec[i] >> 3);
244  out[i] += dec->newvec[i];
245  }
246 }
247 
248 static void truespeech_synth(TSContext *dec, int16_t *out, int quart)
249 {
250  int i,k;
251  int t[8];
252  int16_t *ptr0, *ptr1;
253 
254  ptr0 = dec->tmp1;
255  ptr1 = dec->filters + quart * 8;
256  for(i = 0; i < 60; i++){
257  int sum = 0;
258  for(k = 0; k < 8; k++)
259  sum += ptr0[k] * (unsigned)ptr1[k];
260  sum = out[i] + ((int)(sum + 0x800U) >> 12);
261  out[i] = av_clip(sum, -0x7FFE, 0x7FFE);
262  for(k = 7; k > 0; k--)
263  ptr0[k] = ptr0[k - 1];
264  ptr0[0] = out[i];
265  }
266 
267  for(i = 0; i < 8; i++)
268  t[i] = (ts_decay_35_64[i] * ptr1[i]) >> 15;
269 
270  ptr0 = dec->tmp2;
271  for(i = 0; i < 60; i++){
272  int sum = 0;
273  for(k = 0; k < 8; k++)
274  sum += ptr0[k] * t[k];
275  for(k = 7; k > 0; k--)
276  ptr0[k] = ptr0[k - 1];
277  ptr0[0] = out[i];
278  out[i] += (- sum) >> 12;
279  }
280 
281  for(i = 0; i < 8; i++)
282  t[i] = (ts_decay_3_4[i] * ptr1[i]) >> 15;
283 
284  ptr0 = dec->tmp3;
285  for(i = 0; i < 60; i++){
286  int sum = out[i] * (1 << 12);
287  for(k = 0; k < 8; k++)
288  sum += ptr0[k] * t[k];
289  for(k = 7; k > 0; k--)
290  ptr0[k] = ptr0[k - 1];
291  ptr0[0] = av_clip((sum + 0x800) >> 12, -0x7FFE, 0x7FFE);
292 
293  sum = ((ptr0[1] * (dec->filtval - (dec->filtval >> 2))) >> 4) + sum;
294  sum = sum - (sum >> 3);
295  out[i] = av_clip((sum + 0x800) >> 12, -0x7FFE, 0x7FFE);
296  }
297 }
298 
300 {
301  int i;
302 
303  for(i = 0; i < 8; i++)
304  c->prevfilt[i] = c->cvector[i];
305 }
306 
307 static int truespeech_decode_frame(AVCodecContext *avctx, void *data,
308  int *got_frame_ptr, AVPacket *avpkt)
309 {
310  AVFrame *frame = data;
311  const uint8_t *buf = avpkt->data;
312  int buf_size = avpkt->size;
313  TSContext *c = avctx->priv_data;
314 
315  int i, j;
316  int16_t *samples;
317  int iterations, ret;
318 
319  iterations = buf_size / 32;
320 
321  if (!iterations) {
322  av_log(avctx, AV_LOG_ERROR,
323  "Too small input buffer (%d bytes), need at least 32 bytes\n", buf_size);
324  return -1;
325  }
326 
327  /* get output buffer */
328  frame->nb_samples = iterations * 240;
329  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
330  return ret;
331  samples = (int16_t *)frame->data[0];
332 
333  memset(samples, 0, iterations * 240 * sizeof(*samples));
334 
335  for(j = 0; j < iterations; j++) {
336  truespeech_read_frame(c, buf);
337  buf += 32;
338 
341 
342  for(i = 0; i < 4; i++) {
347  samples += 60;
348  }
349 
351  }
352 
353  *got_frame_ptr = 1;
354 
355  return buf_size;
356 }
357 
359  .name = "truespeech",
360  .long_name = NULL_IF_CONFIG_SMALL("DSP Group TrueSpeech"),
361  .type = AVMEDIA_TYPE_AUDIO,
363  .priv_data_size = sizeof(TSContext),
366  .capabilities = AV_CODEC_CAP_DR1,
367  .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
368 };
AVCodec
AVCodec.
Definition: codec.h:202
bswapdsp.h
FF_CODEC_CAP_INIT_THREADSAFE
#define FF_CODEC_CAP_INIT_THREADSAFE
The codec does not modify any global variables in the init function, allowing to call the init functi...
Definition: internal.h:42
av_clip
#define av_clip
Definition: common.h:96
init
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:31
AVCodecContext::channel_layout
uint64_t channel_layout
Audio channel layout.
Definition: avcodec.h:1043
mem_internal.h
out
FILE * out
Definition: movenc.c:54
truespeech_decode_init
static av_cold int truespeech_decode_init(AVCodecContext *avctx)
Definition: truespeech.c:63
AV_CH_LAYOUT_MONO
#define AV_CH_LAYOUT_MONO
Definition: channel_layout.h:90
get_bits_long
static unsigned int get_bits_long(GetBitContext *s, int n)
Read 0-32 bits.
Definition: get_bits.h:547
TSContext::flag
int flag
1-bit flag, shows how to choose filters
Definition: truespeech.c:50
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:303
tmp
static uint8_t tmp[11]
Definition: aes_ctr.c:26
internal.h
AVPacket::data
uint8_t * data
Definition: packet.h:373
TSContext::filters
int16_t filters[32]
Definition: truespeech.c:60
data
const char data[16]
Definition: mxf.c:143
TSContext::pulseoff
int pulseoff[4]
4-bit offset of pulse values block
Definition: truespeech.c:47
TSContext::tmp1
int16_t tmp1[8]
Definition: truespeech.c:54
filter
filter_frame For filters that do not use the this method is called when a frame is pushed to the filter s input It can be called at any time except in a reentrant way If the input frame is enough to produce then the filter should push the output frames on the output link immediately As an exception to the previous rule if the input frame is enough to produce several output frames then the filter needs output only at least one per link The additional frames can be left buffered in the filter
Definition: filter_design.txt:228
TSContext::filtval
int filtval
Definition: truespeech.c:58
init_get_bits
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:660
get_bits
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:380
GetBitContext
Definition: get_bits.h:62
TSContext::offset2
int offset2[4]
7-bit value, encodes offsets for copying and for two-point filter
Definition: truespeech.c:46
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
av_cold
#define av_cold
Definition: attributes.h:90
decode
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
TSContext::pulsepos
int pulsepos[4]
27-bit variable, encodes 7 pulse positions
Definition: truespeech.c:48
intreadwrite.h
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
BswapDSPContext::bswap_buf
void(* bswap_buf)(uint32_t *dst, const uint32_t *src, int w)
Definition: bswapdsp.h:25
TSContext::tmp2
int16_t tmp2[8]
Definition: truespeech.c:55
get_bits.h
truespeech_read_frame
static void truespeech_read_frame(TSContext *dec, const uint8_t *input)
Definition: truespeech.c:80
truespeech_update_filters
static void truespeech_update_filters(TSContext *dec, int16_t *out, int quart)
Definition: truespeech.c:237
ff_bswapdsp_init
av_cold void ff_bswapdsp_init(BswapDSPContext *c)
Definition: bswapdsp.c:49
AVERROR_PATCHWELCOME
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:64
ts_decay_35_64
static const int16_t ts_decay_35_64[8]
Definition: truespeech_data.h:154
get_bits1
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:499
ff_truespeech_decoder
const AVCodec ff_truespeech_decoder
Definition: truespeech.c:358
ts_decay_3_4
static const int16_t ts_decay_3_4[8]
Definition: truespeech_data.h:156
ts_pulse_scales
static const int16_t ts_pulse_scales[64]
Definition: truespeech_data.h:134
truespeech_place_pulses
static void truespeech_place_pulses(TSContext *dec, int16_t *out, int quart)
Definition: truespeech.c:194
c
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
truespeech_data.h
TSContext::offset1
int offset1[2]
8-bit value, used in one copying offset
Definition: truespeech.c:45
ff_get_buffer
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1652
AV_CODEC_CAP_DR1
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:52
AVPacket::size
int size
Definition: packet.h:374
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
AVCodecContext::sample_fmt
enum AVSampleFormat sample_fmt
audio sample format
Definition: avcodec.h:1000
TSContext::prevfilt
int prevfilt[8]
Definition: truespeech.c:53
TSContext::tmp3
int16_t tmp3[8]
Definition: truespeech.c:56
TSContext::vector
int16_t vector[8]
input vector: 5/5/4/4/4/3/3/3
Definition: truespeech.c:44
input
and forward the test the status of outputs and forward it to the corresponding return FFERROR_NOT_READY If the filters stores internally one or a few frame for some input
Definition: filter_design.txt:172
AVCodecContext::channels
int channels
number of audio channels
Definition: avcodec.h:993
DECLARE_ALIGNED
#define DECLARE_ALIGNED(n, t, v)
Definition: mem.h:116
ts_decay_994_1000
static const int16_t ts_decay_994_1000[8]
Definition: truespeech_data.h:97
i
int i
Definition: input.c:406
ts_order2_coeffs
static const int16_t ts_order2_coeffs[25 *2]
Definition: truespeech_data.h:101
TSContext
TrueSpeech decoder context.
Definition: truespeech.c:40
AV_SAMPLE_FMT_S16
@ AV_SAMPLE_FMT_S16
signed 16 bits
Definition: samplefmt.h:61
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:209
truespeech_filters_merge
static void truespeech_filters_merge(TSContext *dec)
Definition: truespeech.c:147
ts_codebook
static const int16_t *const ts_codebook[8]
Definition: truespeech_data.h:69
avcodec.h
ret
ret
Definition: filter_design.txt:187
frame
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
Definition: filter_design.txt:264
TSContext::newvec
int16_t newvec[60]
Definition: truespeech.c:59
AVCodecContext
main external API structure.
Definition: avcodec.h:383
TSContext::cvector
int16_t cvector[8]
Definition: truespeech.c:57
truespeech_save_prevvec
static void truespeech_save_prevvec(TSContext *c)
Definition: truespeech.c:299
channel_layout.h
samples
Filter the word “frame” indicates either a video frame or a group of audio samples
Definition: filter_design.txt:8
AV_CODEC_ID_TRUESPEECH
@ AV_CODEC_ID_TRUESPEECH
Definition: codec_id.h:443
TSContext::bdsp
BswapDSPContext bdsp
Definition: truespeech.c:41
avpriv_request_sample
#define avpriv_request_sample(...)
Definition: tableprint_vlc.h:37
AVPacket
This structure stores compressed data.
Definition: packet.h:350
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:410
TSContext::pulseval
int pulseval[4]
7x2-bit pulse values
Definition: truespeech.c:49
TSContext::filtbuf
int filtbuf[146]
Definition: truespeech.c:52
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28
BswapDSPContext
Definition: bswapdsp.h:24
truespeech_synth
static void truespeech_synth(TSContext *dec, int16_t *out, int quart)
Definition: truespeech.c:248
ts_pulse_values
static const int16_t ts_pulse_values[120]
Definition: truespeech_data.h:74
TSContext::buffer
uint8_t buffer[32]
Definition: truespeech.c:43
int
int
Definition: ffmpeg_filter.c:156
truespeech_decode_frame
static int truespeech_decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt)
Definition: truespeech.c:307
truespeech_correlate_filter
static void truespeech_correlate_filter(TSContext *dec)
Definition: truespeech.c:128
truespeech_apply_twopoint_filter
static void truespeech_apply_twopoint_filter(TSContext *dec, int quart)
Definition: truespeech.c:168