/*
  * Raw FLAC demuxer
  * Copyright (c) 2001 Fabrice Bellard
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 

 #include "libavcodec/flac.h"

 #include "avformat.h"

 #include "rawdec.h"

 #include "oggdec.h"

 #include "vorbiscomment.h"

 
 static int flac_read_header(AVFormatContext *s,
                              AVFormatParameters *ap)
 {

     int ret, metadata_last=0, metadata_type, metadata_size, found_streaminfo=0;
     uint8_t header[4];
     uint8_t *buffer=NULL;

     AVStream *st = av_new_stream(s, 0);
     if (!st)
         return AVERROR(ENOMEM);

     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;

     st->codec->codec_id = CODEC_ID_FLAC;
     st->need_parsing = AVSTREAM_PARSE_FULL;
     /* the parameters will be extracted from the compressed bitstream */
 

     /* if fLaC marker is not found, assume there is no header */

     if (avio_rl32(s->pb) != MKTAG('f','L','a','C')) {

         avio_seek(s->pb, -4, SEEK_CUR);

         return 0;

     }

 
     /* process metadata blocks */
     while (!url_feof(s->pb) && !metadata_last) {

         avio_read(s->pb, header, 4);

         ff_flac_parse_block_header(header, &metadata_last, &metadata_type,
                                    &metadata_size);
         switch (metadata_type) {
         /* allocate and read metadata block for supported types */
         case FLAC_METADATA_TYPE_STREAMINFO:
         case FLAC_METADATA_TYPE_VORBIS_COMMENT:
             buffer = av_mallocz(metadata_size + FF_INPUT_BUFFER_PADDING_SIZE);
             if (!buffer) {

                 return AVERROR(ENOMEM);

             }

             if (avio_read(s->pb, buffer, metadata_size) != metadata_size) {

                 av_freep(&buffer);

                 return AVERROR(EIO);

             }
             break;
         /* skip metadata block for unsupported types */
         default:

             ret = avio_skip(s->pb, metadata_size);

             if (ret < 0)
                 return ret;
         }
 
         if (metadata_type == FLAC_METADATA_TYPE_STREAMINFO) {
             FLACStreaminfo si;
             /* STREAMINFO can only occur once */
             if (found_streaminfo) {
                 av_freep(&buffer);
                 return AVERROR_INVALIDDATA;
             }
             if (metadata_size != FLAC_STREAMINFO_SIZE) {
                 av_freep(&buffer);
                 return AVERROR_INVALIDDATA;
             }
             found_streaminfo = 1;
             st->codec->extradata      = buffer;
             st->codec->extradata_size = metadata_size;
             buffer = NULL;
 
             /* get codec params from STREAMINFO header */
             ff_flac_parse_streaminfo(st->codec, &si, st->codec->extradata);
 
             /* set time base and duration */
             if (si.samplerate > 0) {
                 av_set_pts_info(st, 64, 1, si.samplerate);
                 if (si.samples > 0)
                     st->duration = si.samples;
             }
         } else {
             /* STREAMINFO must be the first block */
             if (!found_streaminfo) {
                 av_freep(&buffer);
                 return AVERROR_INVALIDDATA;
             }
             /* process supported blocks other than STREAMINFO */
             if (metadata_type == FLAC_METADATA_TYPE_VORBIS_COMMENT) {

                 if (ff_vorbis_comment(s, &s->metadata, buffer, metadata_size)) {

                     av_log(s, AV_LOG_WARNING, "error parsing VorbisComment metadata\n");
                 }
             }
             av_freep(&buffer);
         }
     }
 

     return 0;
 }
 
 static int flac_probe(AVProbeData *p)
 {
     uint8_t *bufptr = p->buf;
     uint8_t *end    = p->buf + p->buf_size;
 
     if(bufptr > end-4 || memcmp(bufptr, "fLaC", 4)) return 0;
     else                                            return AVPROBE_SCORE_MAX/2;
 }
 

 AVInputFormat ff_flac_demuxer = {

     "flac",
     NULL_IF_CONFIG_SMALL("raw FLAC"),
     0,
     flac_probe,
     flac_read_header,
     ff_raw_read_partial_packet,
     .flags= AVFMT_GENERIC_INDEX,
     .extensions = "flac",
     .value = CODEC_ID_FLAC,
 };