FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
libvorbisdec.c
Go to the documentation of this file.
1 /*
2  * Copyright (c) 2002 Mark Hills <mark@pogo.org.uk>
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include <vorbis/vorbisenc.h>
22 
23 #include "avcodec.h"
24 #include "bytestream.h"
25 #include "internal.h"
26 
27 typedef struct OggVorbisDecContext {
28  vorbis_info vi; /**< vorbis_info used during init */
29  vorbis_dsp_state vd; /**< DSP state used for analysis */
30  vorbis_block vb; /**< vorbis_block used for analysis */
31  vorbis_comment vc; /**< VorbisComment info */
32  ogg_packet op; /**< ogg packet */
34 
35 static int oggvorbis_decode_init(AVCodecContext *avccontext) {
36  OggVorbisDecContext *context = avccontext->priv_data ;
37  uint8_t *p= avccontext->extradata;
38  int i, hsizes[3], ret;
39  unsigned char *headers[3], *extradata = avccontext->extradata;
40 
41  if(! avccontext->extradata_size || ! p) {
42  av_log(avccontext, AV_LOG_ERROR, "vorbis extradata absent\n");
43  return AVERROR(EINVAL);
44  }
45 
46  vorbis_info_init(&context->vi) ;
47  vorbis_comment_init(&context->vc) ;
48 
49  if(p[0] == 0 && p[1] == 30) {
50  for(i = 0; i < 3; i++){
51  hsizes[i] = bytestream_get_be16((const uint8_t **)&p);
52  headers[i] = p;
53  p += hsizes[i];
54  }
55  } else if(*p == 2) {
56  unsigned int offset = 1;
57  p++;
58  for(i=0; i<2; i++) {
59  hsizes[i] = 0;
60  while((*p == 0xFF) && (offset < avccontext->extradata_size)) {
61  hsizes[i] += 0xFF;
62  offset++;
63  p++;
64  }
65  if(offset >= avccontext->extradata_size - 1) {
66  av_log(avccontext, AV_LOG_ERROR,
67  "vorbis header sizes damaged\n");
68  ret = AVERROR_INVALIDDATA;
69  goto error;
70  }
71  hsizes[i] += *p;
72  offset++;
73  p++;
74  }
75  hsizes[2] = avccontext->extradata_size - hsizes[0]-hsizes[1]-offset;
76 #if 0
77  av_log(avccontext, AV_LOG_DEBUG,
78  "vorbis header sizes: %d, %d, %d, / extradata_len is %d \n",
79  hsizes[0], hsizes[1], hsizes[2], avccontext->extradata_size);
80 #endif
81  headers[0] = extradata + offset;
82  headers[1] = extradata + offset + hsizes[0];
83  headers[2] = extradata + offset + hsizes[0] + hsizes[1];
84  } else {
85  av_log(avccontext, AV_LOG_ERROR,
86  "vorbis initial header len is wrong: %d\n", *p);
87  ret = AVERROR_INVALIDDATA;
88  goto error;
89  }
90 
91  for(i=0; i<3; i++){
92  context->op.b_o_s= i==0;
93  context->op.bytes = hsizes[i];
94  context->op.packet = headers[i];
95  if(vorbis_synthesis_headerin(&context->vi, &context->vc, &context->op)<0){
96  av_log(avccontext, AV_LOG_ERROR, "%d. vorbis header damaged\n", i+1);
97  ret = AVERROR_INVALIDDATA;
98  goto error;
99  }
100  }
101 
102  avccontext->channels = context->vi.channels;
103  avccontext->sample_rate = context->vi.rate;
104  avccontext->sample_fmt = AV_SAMPLE_FMT_S16;
105  avccontext->time_base= (AVRational){1, avccontext->sample_rate};
106 
107  vorbis_synthesis_init(&context->vd, &context->vi);
108  vorbis_block_init(&context->vd, &context->vb);
109 
110  return 0 ;
111 
112  error:
113  vorbis_info_clear(&context->vi);
114  vorbis_comment_clear(&context->vc) ;
115  return ret;
116 }
117 
118 
119 static inline int conv(int samples, float **pcm, char *buf, int channels) {
120  int i, j;
121  ogg_int16_t *ptr, *data = (ogg_int16_t*)buf ;
122  float *mono ;
123 
124  for(i = 0 ; i < channels ; i++){
125  ptr = &data[i];
126  mono = pcm[i] ;
127 
128  for(j = 0 ; j < samples ; j++) {
129  *ptr = av_clip_int16(mono[j] * 32767.f);
130  ptr += channels;
131  }
132  }
133 
134  return 0 ;
135 }
136 
137 static int oggvorbis_decode_frame(AVCodecContext *avccontext, void *data,
138  int *got_frame_ptr, AVPacket *avpkt)
139 {
140  OggVorbisDecContext *context = avccontext->priv_data ;
141  AVFrame *frame = data;
142  float **pcm ;
143  ogg_packet *op= &context->op;
144  int samples, total_samples, total_bytes;
145  int ret;
146  int16_t *output;
147 
148  if(!avpkt->size){
149  //FIXME flush
150  return 0;
151  }
152 
153  frame->nb_samples = 8192*4;
154  if ((ret = ff_get_buffer(avccontext, frame, 0)) < 0)
155  return ret;
156  output = (int16_t *)frame->data[0];
157 
158 
159  op->packet = avpkt->data;
160  op->bytes = avpkt->size;
161 
162 // av_log(avccontext, AV_LOG_DEBUG, "%d %d %d %"PRId64" %"PRId64" %d %d\n", op->bytes, op->b_o_s, op->e_o_s, op->granulepos, op->packetno, buf_size, context->vi.rate);
163 
164 /* for(i=0; i<op->bytes; i++)
165  av_log(avccontext, AV_LOG_DEBUG, "%02X ", op->packet[i]);
166  av_log(avccontext, AV_LOG_DEBUG, "\n");*/
167 
168  if(vorbis_synthesis(&context->vb, op) == 0)
169  vorbis_synthesis_blockin(&context->vd, &context->vb) ;
170 
171  total_samples = 0 ;
172  total_bytes = 0 ;
173 
174  while((samples = vorbis_synthesis_pcmout(&context->vd, &pcm)) > 0) {
175  conv(samples, pcm, (char*)output + total_bytes, context->vi.channels) ;
176  total_bytes += samples * 2 * context->vi.channels ;
177  total_samples += samples ;
178  vorbis_synthesis_read(&context->vd, samples) ;
179  }
180 
181  frame->nb_samples = total_samples;
182  *got_frame_ptr = total_samples > 0;
183  return avpkt->size;
184 }
185 
186 
187 static int oggvorbis_decode_close(AVCodecContext *avccontext) {
188  OggVorbisDecContext *context = avccontext->priv_data ;
189 
190  vorbis_info_clear(&context->vi) ;
191  vorbis_comment_clear(&context->vc) ;
192 
193  return 0 ;
194 }
195 
196 
198  .name = "libvorbis",
199  .long_name = NULL_IF_CONFIG_SMALL("libvorbis"),
200  .type = AVMEDIA_TYPE_AUDIO,
201  .id = AV_CODEC_ID_VORBIS,
202  .priv_data_size = sizeof(OggVorbisDecContext),
205  .close = oggvorbis_decode_close,
206  .capabilities = CODEC_CAP_DELAY,
207 };