• Main Page
  • Related Pages
  • Modules
  • Data Structures
  • Files
  • File List
  • Globals

libavcodec/libvorbis.c

Go to the documentation of this file.
00001 /*
00002  * copyright (c) 2002 Mark Hills <mark@pogo.org.uk>
00003  *
00004  * This file is part of FFmpeg.
00005  *
00006  * FFmpeg is free software; you can redistribute it and/or
00007  * modify it under the terms of the GNU Lesser General Public
00008  * License as published by the Free Software Foundation; either
00009  * version 2.1 of the License, or (at your option) any later version.
00010  *
00011  * FFmpeg is distributed in the hope that it will be useful,
00012  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00013  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00014  * Lesser General Public License for more details.
00015  *
00016  * You should have received a copy of the GNU Lesser General Public
00017  * License along with FFmpeg; if not, write to the Free Software
00018  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00019  */
00020 
00027 #include <vorbis/vorbisenc.h>
00028 
00029 #include "avcodec.h"
00030 #include "bytestream.h"
00031 
00032 #undef NDEBUG
00033 #include <assert.h>
00034 
00035 #define OGGVORBIS_FRAME_SIZE 64
00036 
00037 #define BUFFER_SIZE (1024*64)
00038 
00039 typedef struct OggVorbisContext {
00040     vorbis_info vi ;
00041     vorbis_dsp_state vd ;
00042     vorbis_block vb ;
00043     uint8_t buffer[BUFFER_SIZE];
00044     int buffer_index;
00045     int eof;
00046 
00047     /* decoder */
00048     vorbis_comment vc ;
00049     ogg_packet op;
00050 } OggVorbisContext ;
00051 
00052 
00053 static av_cold int oggvorbis_init_encoder(vorbis_info *vi, AVCodecContext *avccontext) {
00054     double cfreq;
00055 
00056     if(avccontext->flags & CODEC_FLAG_QSCALE) {
00057         /* variable bitrate */
00058         if(vorbis_encode_setup_vbr(vi, avccontext->channels,
00059                 avccontext->sample_rate,
00060                 avccontext->global_quality / (float)FF_QP2LAMBDA / 10.0))
00061             return -1;
00062     } else {
00063         /* constant bitrate */
00064         if(vorbis_encode_setup_managed(vi, avccontext->channels,
00065                 avccontext->sample_rate, -1, avccontext->bit_rate, -1))
00066             return -1;
00067 
00068 #ifdef OGGVORBIS_VBR_BY_ESTIMATE
00069         /* variable bitrate by estimate */
00070         if(vorbis_encode_ctl(vi, OV_ECTL_RATEMANAGE_AVG, NULL))
00071             return -1;
00072 #endif
00073     }
00074 
00075     /* cutoff frequency */
00076     if(avccontext->cutoff > 0) {
00077         cfreq = avccontext->cutoff / 1000.0;
00078         if(vorbis_encode_ctl(vi, OV_ECTL_LOWPASS_SET, &cfreq))
00079             return -1;
00080     }
00081 
00082     return vorbis_encode_setup_init(vi);
00083 }
00084 
00085 static av_cold int oggvorbis_encode_init(AVCodecContext *avccontext) {
00086     OggVorbisContext *context = avccontext->priv_data ;
00087     ogg_packet header, header_comm, header_code;
00088     uint8_t *p;
00089     unsigned int offset, len;
00090 
00091     vorbis_info_init(&context->vi) ;
00092     if(oggvorbis_init_encoder(&context->vi, avccontext) < 0) {
00093         av_log(avccontext, AV_LOG_ERROR, "oggvorbis_encode_init: init_encoder failed\n") ;
00094         return -1 ;
00095     }
00096     vorbis_analysis_init(&context->vd, &context->vi) ;
00097     vorbis_block_init(&context->vd, &context->vb) ;
00098 
00099     vorbis_comment_init(&context->vc);
00100     vorbis_comment_add_tag(&context->vc, "encoder", LIBAVCODEC_IDENT) ;
00101 
00102     vorbis_analysis_headerout(&context->vd, &context->vc, &header,
00103                                 &header_comm, &header_code);
00104 
00105     len = header.bytes + header_comm.bytes +  header_code.bytes;
00106     avccontext->extradata_size= 64 + len + len/255;
00107     p = avccontext->extradata= av_mallocz(avccontext->extradata_size);
00108     p[0] = 2;
00109     offset = 1;
00110     offset += av_xiphlacing(&p[offset], header.bytes);
00111     offset += av_xiphlacing(&p[offset], header_comm.bytes);
00112     memcpy(&p[offset], header.packet, header.bytes);
00113     offset += header.bytes;
00114     memcpy(&p[offset], header_comm.packet, header_comm.bytes);
00115     offset += header_comm.bytes;
00116     memcpy(&p[offset], header_code.packet, header_code.bytes);
00117     offset += header_code.bytes;
00118     avccontext->extradata_size = offset;
00119     avccontext->extradata= av_realloc(avccontext->extradata, avccontext->extradata_size);
00120 
00121 /*    vorbis_block_clear(&context->vb);
00122     vorbis_dsp_clear(&context->vd);
00123     vorbis_info_clear(&context->vi);*/
00124     vorbis_comment_clear(&context->vc);
00125 
00126     avccontext->frame_size = OGGVORBIS_FRAME_SIZE ;
00127 
00128     avccontext->coded_frame= avcodec_alloc_frame();
00129     avccontext->coded_frame->key_frame= 1;
00130 
00131     return 0 ;
00132 }
00133 
00134 
00135 static int oggvorbis_encode_frame(AVCodecContext *avccontext,
00136                                   unsigned char *packets,
00137                            int buf_size, void *data)
00138 {
00139     OggVorbisContext *context = avccontext->priv_data ;
00140     ogg_packet op ;
00141     signed short *audio = data ;
00142     int l;
00143 
00144     if(data) {
00145         int samples = OGGVORBIS_FRAME_SIZE;
00146         float **buffer ;
00147 
00148         buffer = vorbis_analysis_buffer(&context->vd, samples) ;
00149         if(context->vi.channels == 1) {
00150             for(l = 0 ; l < samples ; l++)
00151                 buffer[0][l]=audio[l]/32768.f;
00152         } else {
00153             for(l = 0 ; l < samples ; l++){
00154                 buffer[0][l]=audio[l*2]/32768.f;
00155                 buffer[1][l]=audio[l*2+1]/32768.f;
00156             }
00157         }
00158         vorbis_analysis_wrote(&context->vd, samples) ;
00159     } else {
00160         if(!context->eof)
00161             vorbis_analysis_wrote(&context->vd, 0) ;
00162         context->eof = 1;
00163     }
00164 
00165     while(vorbis_analysis_blockout(&context->vd, &context->vb) == 1) {
00166         vorbis_analysis(&context->vb, NULL);
00167         vorbis_bitrate_addblock(&context->vb) ;
00168 
00169         while(vorbis_bitrate_flushpacket(&context->vd, &op)) {
00170             /* i'd love to say the following line is a hack, but sadly it's
00171              * not, apparently the end of stream decision is in libogg. */
00172             if(op.bytes==1)
00173                 continue;
00174             memcpy(context->buffer + context->buffer_index, &op, sizeof(ogg_packet));
00175             context->buffer_index += sizeof(ogg_packet);
00176             memcpy(context->buffer + context->buffer_index, op.packet, op.bytes);
00177             context->buffer_index += op.bytes;
00178 //            av_log(avccontext, AV_LOG_DEBUG, "e%d / %d\n", context->buffer_index, op.bytes);
00179         }
00180     }
00181 
00182     l=0;
00183     if(context->buffer_index){
00184         ogg_packet *op2= (ogg_packet*)context->buffer;
00185         op2->packet = context->buffer + sizeof(ogg_packet);
00186 
00187         l=  op2->bytes;
00188         avccontext->coded_frame->pts= av_rescale_q(op2->granulepos, (AVRational){1, avccontext->sample_rate}, avccontext->time_base);
00189         //FIXME we should reorder the user supplied pts and not assume that they are spaced by 1/sample_rate
00190 
00191         memcpy(packets, op2->packet, l);
00192         context->buffer_index -= l + sizeof(ogg_packet);
00193         memcpy(context->buffer, context->buffer + l + sizeof(ogg_packet), context->buffer_index);
00194 //        av_log(avccontext, AV_LOG_DEBUG, "E%d\n", l);
00195     }
00196 
00197     return l;
00198 }
00199 
00200 
00201 static av_cold int oggvorbis_encode_close(AVCodecContext *avccontext) {
00202     OggVorbisContext *context = avccontext->priv_data ;
00203 /*  ogg_packet op ; */
00204 
00205     vorbis_analysis_wrote(&context->vd, 0) ; /* notify vorbisenc this is EOF */
00206 
00207     vorbis_block_clear(&context->vb);
00208     vorbis_dsp_clear(&context->vd);
00209     vorbis_info_clear(&context->vi);
00210 
00211     av_freep(&avccontext->coded_frame);
00212     av_freep(&avccontext->extradata);
00213 
00214     return 0 ;
00215 }
00216 
00217 
00218 AVCodec libvorbis_encoder = {
00219     "libvorbis",
00220     AVMEDIA_TYPE_AUDIO,
00221     CODEC_ID_VORBIS,
00222     sizeof(OggVorbisContext),
00223     oggvorbis_encode_init,
00224     oggvorbis_encode_frame,
00225     oggvorbis_encode_close,
00226     .capabilities= CODEC_CAP_DELAY,
00227     .sample_fmts = (const enum SampleFormat[]){SAMPLE_FMT_S16,SAMPLE_FMT_NONE},
00228     .long_name= NULL_IF_CONFIG_SMALL("libvorbis Vorbis"),
00229 } ;

Generated on Fri Sep 16 2011 17:17:38 for FFmpeg by  doxygen 1.7.1