2 * Ogg bitstream support
3 * Mark Hills <mark@pogo.org.uk>
5 * Uses libogg, but requires libvorbisenc to construct correct headers
6 * when containing Vorbis stream -- currently the only format supported
18 #define DECODER_BUFFER_SIZE 4096
21 typedef struct OggContext {
33 static int ogg_write_header(AVFormatContext *avfcontext)
35 OggContext *context = avfcontext->priv_data;
36 ogg_packet *op= &context->op;
39 ogg_stream_init(&context->os, 31415);
41 for(n = 0 ; n < avfcontext->nb_streams ; n++) {
42 AVCodecContext *codec = avfcontext->streams[n]->codec;
43 uint8_t *headers = codec->extradata;
44 int headers_len = codec->extradata_size;
45 uint8_t *header_start[3];
49 av_set_pts_info(avfcontext->streams[n], 60, 1, AV_TIME_BASE);
51 for(j=1,i=0;i<2;++i, ++j) {
53 while(j<headers_len && headers[j]==0xff) {
57 header_len[i]+=headers[j];
59 header_len[2]=headers_len-header_len[0]-header_len[1]-j;
61 header_start[0] = headers;
62 header_start[1] = header_start[0] + header_len[0];
63 header_start[2] = header_start[1] + header_len[1];
66 op->bytes = header_len[i];
68 op->packet= header_start[i];
69 op->b_o_s= op->packetno==0;
71 ogg_stream_packetin(&context->os, op);
73 op->packetno++; //FIXME multiple streams
76 context->header_handled = 0 ;
82 static int ogg_write_packet(AVFormatContext *avfcontext, AVPacket *pkt)
84 OggContext *context = avfcontext->priv_data ;
85 AVCodecContext *avctx= avfcontext->streams[pkt->stream_index]->codec;
86 ogg_packet *op= &context->op;
90 pts= av_rescale(pkt->pts, avctx->sample_rate, AV_TIME_BASE);
92 // av_log(avfcontext, AV_LOG_DEBUG, "M%d\n", size);
94 /* flush header packets so audio starts on a new page */
96 if(!context->header_handled) {
97 while(ogg_stream_flush(&context->os, &og)) {
98 put_buffer(&avfcontext->pb, og.header, og.header_len) ;
99 put_buffer(&avfcontext->pb, og.body, og.body_len) ;
100 put_flush_packet(&avfcontext->pb);
102 context->header_handled = 1 ;
105 op->packet = (uint8_t*) pkt->data;
106 op->bytes = pkt->size;
107 op->b_o_s = op->packetno == 0;
110 /* correct the fields in the packet -- essential for streaming */
112 ogg_stream_packetin(&context->os, op);
114 while(ogg_stream_pageout(&context->os, &og)) {
115 put_buffer(&avfcontext->pb, og.header, og.header_len);
116 put_buffer(&avfcontext->pb, og.body, og.body_len);
117 put_flush_packet(&avfcontext->pb);
125 static int ogg_write_trailer(AVFormatContext *avfcontext) {
126 OggContext *context = avfcontext->priv_data ;
129 while(ogg_stream_flush(&context->os, &og)) {
130 put_buffer(&avfcontext->pb, og.header, og.header_len) ;
131 put_buffer(&avfcontext->pb, og.body, og.body_len) ;
132 put_flush_packet(&avfcontext->pb);
135 ogg_stream_clear(&context->os) ;
140 static AVOutputFormat ogg_oformat = {
152 #endif //CONFIG_MUXERS
155 static int next_packet(AVFormatContext *avfcontext, ogg_packet *op) {
156 OggContext *context = avfcontext->priv_data ;
160 while(ogg_stream_packetout(&context->os, op) != 1) {
162 /* while no pages are available, read in more data to the sync */
163 while(ogg_sync_pageout(&context->oy, &og) != 1) {
164 buf = ogg_sync_buffer(&context->oy, DECODER_BUFFER_SIZE) ;
165 if(get_buffer(&avfcontext->pb, buf, DECODER_BUFFER_SIZE) <= 0)
167 ogg_sync_wrote(&context->oy, DECODER_BUFFER_SIZE) ;
170 /* got a page. Feed it into the stream and get the packet */
171 if(ogg_stream_pagein(&context->os, &og) != 0)
179 static int ogg_read_header(AVFormatContext *avfcontext, AVFormatParameters *ap)
181 OggContext *context = avfcontext->priv_data;
186 AVCodecContext *codec;
190 ogg_sync_init(&context->oy) ;
191 buf = ogg_sync_buffer(&context->oy, DECODER_BUFFER_SIZE) ;
193 if(get_buffer(&avfcontext->pb, buf, DECODER_BUFFER_SIZE) <= 0)
196 ogg_sync_wrote(&context->oy, DECODER_BUFFER_SIZE) ;
197 ogg_sync_pageout(&context->oy, &og) ;
198 ogg_stream_init(&context->os, ogg_page_serialno(&og)) ;
199 ogg_stream_pagein(&context->os, &og) ;
201 /* currently only one vorbis stream supported */
203 ast = av_new_stream(avfcontext, 0) ;
205 return AVERROR_NOMEM ;
206 av_set_pts_info(ast, 60, 1, AV_TIME_BASE);
209 codec->codec_type = CODEC_TYPE_AUDIO;
210 codec->codec_id = CODEC_ID_VORBIS;
212 if(next_packet(avfcontext, &op)){
215 if(op.bytes >= (1<<16) || op.bytes < 0)
217 codec->extradata_size+= 2 + op.bytes;
218 codec->extradata= av_realloc(codec->extradata, codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
219 memset(codec->extradata + codec->extradata_size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
220 p= codec->extradata + codec->extradata_size - 2 - op.bytes;
222 *(p++)= op.bytes&0xFF;
223 memcpy(p, op.packet, op.bytes);
230 static int ogg_read_packet(AVFormatContext *avfcontext, AVPacket *pkt) {
233 if(next_packet(avfcontext, &op))
235 if(av_new_packet(pkt, op.bytes) < 0)
237 pkt->stream_index = 0 ;
238 memcpy(pkt->data, op.packet, op.bytes);
239 if(avfcontext->streams[0]->codec.sample_rate && op.granulepos!=-1)
240 pkt->pts= av_rescale(op.granulepos, AV_TIME_BASE, avfcontext->streams[0]->codec.sample_rate);
241 // printf("%lld %d %d\n", pkt->pts, (int)op.granulepos, avfcontext->streams[0]->codec.sample_rate);
247 static int ogg_read_close(AVFormatContext *avfcontext) {
248 OggContext *context = avfcontext->priv_data ;
250 ogg_stream_clear(&context->os) ;
251 ogg_sync_clear(&context->oy) ;
257 static AVInputFormat ogg_iformat = {
269 int libogg_init(void) {
271 av_register_output_format(&ogg_oformat) ;
273 /* av_register_input_format(&ogg_iformat); */