FFmpeg: libavcodec/libvorbisdec.c Source File

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libavcodec

libvorbisdec.c

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1 /*

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 */

21 #include <vorbis/vorbisenc.h>

23 #include "avcodec.h"

24 #include "bytestream.h"

25 #include "internal.h"

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 */

33 } OggVorbisDecContext;

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;

41 if(! avccontext->extradata_size || ! p) {

42 av_log(avccontext, AV_LOG_ERROR, "vorbis extradata absent\n");

43 return AVERROR(EINVAL);

44 }

46 vorbis_info_init(&context->vi) ;

47 vorbis_comment_init(&context->vc) ;

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 }

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

197 AVCodec ff_libvorbis_decoder = {

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),

203 .init = oggvorbis_decode_init,

204 .decode = oggvorbis_decode_frame,

205 .close = oggvorbis_decode_close,

206 .capabilities = CODEC_CAP_DELAY,

207 };

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