/* * Ogg bitstream support * Mark Hills <mark@pogo.org.uk> * * Uses libogg, but requires libvorbisenc to construct correct headers * when containing Vorbis stream -- currently the only format supported */ #include <stdio.h> #include <time.h> #include <ogg/ogg.h> #include <vorbis/vorbisenc.h> #include "avformat.h" #include "oggvorbis.h" #define DECODER_BUFFER_SIZE 4096 typedef struct OggContext { /* output */ ogg_stream_state os ; int header_handled ; ogg_int64_t base_packet_no ; ogg_int64_t base_granule_pos ; /* input */ ogg_sync_state oy ; } OggContext ; static int ogg_write_header(AVFormatContext *avfcontext) { OggContext *context ; AVCodecContext *avccontext ; vorbis_info vi ; vorbis_dsp_state vd ; vorbis_comment vc ; vorbis_block vb ; ogg_packet header, header_comm, header_code ; int n ; if(!(context = malloc(sizeof(OggContext)))) return -1 ; avfcontext->priv_data = context ; srand(time(NULL)); ogg_stream_init(&context->os, rand()); for(n = 0 ; n < avfcontext->nb_streams ; n++) { avccontext = &avfcontext->streams[n]->codec ; /* begin vorbis specific code */ vorbis_info_init(&vi) ; /* code copied from libavcodec/oggvorbis.c */ if(oggvorbis_init_encoder(&vi, avccontext) < 0) { fprintf(stderr, "ogg_write_header: init_encoder failed") ; return -1 ; } vorbis_analysis_init(&vd, &vi) ; vorbis_block_init(&vd, &vb) ; vorbis_comment_init(&vc) ; vorbis_comment_add_tag(&vc, "encoder", "ffmpeg") ; if(*avfcontext->title) vorbis_comment_add_tag(&vc, "title", avfcontext->title) ; vorbis_analysis_headerout(&vd, &vc, &header, &header_comm, &header_code) ; ogg_stream_packetin(&context->os, &header) ; ogg_stream_packetin(&context->os, &header_comm) ; ogg_stream_packetin(&context->os, &header_code) ; vorbis_comment_clear(&vc) ; /* end of vorbis specific code */ context->header_handled = 0 ; context->base_packet_no = 0 ; } return 0 ; } static int ogg_write_packet(AVFormatContext *avfcontext, int stream_index, unsigned char *buf, int size, int force_pts) { OggContext *context = avfcontext->priv_data ; ogg_packet *op ; ogg_page og ; int l = 0 ; /* flush header packets so audio starts on a new page */ if(!context->header_handled) { while(ogg_stream_flush(&context->os, &og)) { put_buffer(&avfcontext->pb, og.header, og.header_len) ; put_buffer(&avfcontext->pb, og.body, og.body_len) ; put_flush_packet(&avfcontext->pb); } context->header_handled = 1 ; } while(l < size) { op = (ogg_packet*)(buf + l) ; op->packet = buf + l + sizeof(ogg_packet) ; /* fix data pointer */ if(!context->base_packet_no) { /* this is the first packet */ context->base_packet_no = op->packetno ; context->base_granule_pos = op->granulepos ; } /* correct the fields in the packet -- essential for streaming */ op->packetno -= context->base_packet_no ; op->granulepos -= context->base_granule_pos ; ogg_stream_packetin(&context->os, op) ; l += sizeof(ogg_packet) + op->bytes ; while(ogg_stream_pageout(&context->os, &og)) { put_buffer(&avfcontext->pb, og.header, og.header_len) ; put_buffer(&avfcontext->pb, og.body, og.body_len) ; put_flush_packet(&avfcontext->pb); } } return 0; } static int ogg_write_trailer(AVFormatContext *avfcontext) { OggContext *context = avfcontext->priv_data ; ogg_page og ; while(ogg_stream_flush(&context->os, &og)) { put_buffer(&avfcontext->pb, og.header, og.header_len) ; put_buffer(&avfcontext->pb, og.body, og.body_len) ; put_flush_packet(&avfcontext->pb); } ogg_stream_clear(&context->os) ; return 0 ; } static AVOutputFormat ogg_oformat = { "ogg", "Ogg Vorbis", "audio/x-vorbis", "ogg", sizeof(OggContext), CODEC_ID_VORBIS, 0, ogg_write_header, ogg_write_packet, ogg_write_trailer, } ; static int next_packet(AVFormatContext *avfcontext, ogg_packet *op) { OggContext *context = avfcontext->priv_data ; ogg_page og ; char *buf ; while(ogg_stream_packetout(&context->os, op) != 1) { /* while no pages are available, read in more data to the sync */ while(ogg_sync_pageout(&context->oy, &og) != 1) { buf = ogg_sync_buffer(&context->oy, DECODER_BUFFER_SIZE) ; if(get_buffer(&avfcontext->pb, buf, DECODER_BUFFER_SIZE) <= 0) return 1 ; ogg_sync_wrote(&context->oy, DECODER_BUFFER_SIZE) ; } /* got a page. Feed it into the stream and get the packet */ if(ogg_stream_pagein(&context->os, &og) != 0) return 1 ; } return 0 ; } static int ogg_read_header(AVFormatContext *avfcontext, AVFormatParameters *ap) { OggContext *context ; char *buf ; ogg_page og ; AVStream *ast ; if(!(context = malloc(sizeof(OggContext)))) { perror("malloc") ; return -1 ; } avfcontext->priv_data = context ; ogg_sync_init(&context->oy) ; buf = ogg_sync_buffer(&context->oy, DECODER_BUFFER_SIZE) ; if(get_buffer(&avfcontext->pb, buf, DECODER_BUFFER_SIZE) <= 0) return -EIO ; ogg_sync_wrote(&context->oy, DECODER_BUFFER_SIZE) ; ogg_sync_pageout(&context->oy, &og) ; ogg_stream_init(&context->os, ogg_page_serialno(&og)) ; ogg_stream_pagein(&context->os, &og) ; /* currently only one vorbis stream supported */ ast = av_new_stream(avfcontext, 0) ; if(!ast) return AVERROR_NOMEM ; ast->codec.codec_type = CODEC_TYPE_AUDIO ; ast->codec.codec_id = CODEC_ID_VORBIS ; return 0 ; } static int ogg_read_packet(AVFormatContext *avfcontext, AVPacket *pkt) { ogg_packet op ; if(next_packet(avfcontext, &op)) return -EIO ; if(av_new_packet(pkt, sizeof(ogg_packet) + op.bytes) < 0) return -EIO ; pkt->stream_index = 0 ; memcpy(pkt->data, &op, sizeof(ogg_packet)) ; memcpy(pkt->data + sizeof(ogg_packet), op.packet, op.bytes) ; return sizeof(ogg_packet) + op.bytes ; } static int ogg_read_close(AVFormatContext *avfcontext) { OggContext *context = avfcontext->priv_data ; ogg_stream_clear(&context->os) ; ogg_sync_clear(&context->oy) ; return 0 ; } static AVInputFormat ogg_iformat = { "ogg", "Ogg Vorbis", sizeof(OggContext), NULL, ogg_read_header, ogg_read_packet, ogg_read_close, .extensions = "ogg", } ; int ogg_init(void) { av_register_output_format(&ogg_oformat) ; av_register_input_format(&ogg_iformat); return 0 ; }