/*
  * 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 "flac_picture.h"

 #include "internal.h"

 #include "rawdec.h"

 #include "oggdec.h"

 #include "vorbiscomment.h"

 #include "replaygain.h"

 static int flac_read_header(AVFormatContext *s)

 {

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

     AVStream *st = avformat_new_stream(s, NULL);

     if (!st)
         return AVERROR(ENOMEM);

     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;

     st->codec->codec_id = AV_CODEC_ID_FLAC;

     st->need_parsing = AVSTREAM_PARSE_FULL_RAW;

     /* 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 (!avio_feof(s->pb) && !metadata_last) {

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

         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_CUESHEET:

         case FLAC_METADATA_TYPE_PICTURE:

         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) {

                 RETURN_ERROR(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) {

             uint32_t samplerate;
             uint64_t samples;
 

             /* STREAMINFO can only occur once */
             if (found_streaminfo) {

                 RETURN_ERROR(AVERROR_INVALIDDATA);

             }
             if (metadata_size != FLAC_STREAMINFO_SIZE) {

                 RETURN_ERROR(AVERROR_INVALIDDATA);

             }
             found_streaminfo = 1;
             st->codec->extradata      = buffer;
             st->codec->extradata_size = metadata_size;
             buffer = NULL;
 

             /* get sample rate and sample count from STREAMINFO header;
              * other parameters will be extracted by the parser */
             samplerate = AV_RB24(st->codec->extradata + 10) >> 4;
             samples    = (AV_RB64(st->codec->extradata + 13) >> 24) & ((1ULL << 36) - 1);

 
             /* set time base and duration */

             if (samplerate > 0) {
                 avpriv_set_pts_info(st, 64, 1, samplerate);
                 if (samples > 0)
                     st->duration = samples;

             }

         } else if (metadata_type == FLAC_METADATA_TYPE_CUESHEET) {
             uint8_t isrc[13];
             uint64_t start;
             const uint8_t *offset;

             int i, chapters, track, ti;

             if (metadata_size < 431)

                 RETURN_ERROR(AVERROR_INVALIDDATA);

             offset = buffer + 395;
             chapters = bytestream_get_byte(&offset) - 1;
             if (chapters <= 0)

                 RETURN_ERROR(AVERROR_INVALIDDATA);

             for (i = 0; i < chapters; i++) {
                 if (offset + 36 - buffer > metadata_size)

                     RETURN_ERROR(AVERROR_INVALIDDATA);

                 start = bytestream_get_be64(&offset);
                 track = bytestream_get_byte(&offset);
                 bytestream_get_buffer(&offset, isrc, 12);
                 isrc[12] = 0;
                 offset += 14;
                 ti = bytestream_get_byte(&offset);

                 if (ti <= 0) RETURN_ERROR(AVERROR_INVALIDDATA);

                 offset += ti * 12;

                 avpriv_new_chapter(s, track, st->time_base, start, AV_NOPTS_VALUE, isrc);
             }

             av_freep(&buffer);

         } else if (metadata_type == FLAC_METADATA_TYPE_PICTURE) {

             ret = ff_flac_parse_picture(s, buffer, metadata_size);

             av_freep(&buffer);
             if (ret < 0) {
                 av_log(s, AV_LOG_ERROR, "Error parsing attached picture.\n");
                 return ret;
             }

         } else {
             /* STREAMINFO must be the first block */
             if (!found_streaminfo) {

                 RETURN_ERROR(AVERROR_INVALIDDATA);

             }
             /* process supported blocks other than STREAMINFO */
             if (metadata_type == FLAC_METADATA_TYPE_VORBIS_COMMENT) {

                 AVDictionaryEntry *chmask;
 

                 ret = ff_vorbis_comment(s, &s->metadata, buffer, metadata_size, 1);
                 if (ret < 0) {

                     av_log(s, AV_LOG_WARNING, "error parsing VorbisComment metadata\n");

                 } else if (ret > 0) {
                     s->event_flags |= AVFMT_EVENT_FLAG_METADATA_UPDATED;

                 }

 
                 /* parse the channels mask if present */
                 chmask = av_dict_get(s->metadata, "WAVEFORMATEXTENSIBLE_CHANNEL_MASK", NULL, 0);
                 if (chmask) {
                     uint64_t mask = strtol(chmask->value, NULL, 0);
                     if (!mask || mask & ~0x3ffffULL) {
                         av_log(s, AV_LOG_WARNING,
                                "Invalid value of WAVEFORMATEXTENSIBLE_CHANNEL_MASK\n");
                     } else {
                         st->codec->channel_layout = mask;
                         av_dict_set(&s->metadata, "WAVEFORMATEXTENSIBLE_CHANNEL_MASK", NULL, 0);
                     }
                 }

             }
             av_freep(&buffer);
         }
     }
 

     ret = ff_replaygain_export(st, s->metadata);
     if (ret < 0)
         return ret;
 

     return 0;

 
 fail:
     av_free(buffer);
     return ret;

 }
 
 static int flac_probe(AVProbeData *p)
 {

     if (p->buf_size < 4 || memcmp(p->buf, "fLaC", 4))
         return 0;

     return AVPROBE_SCORE_EXTENSION;

 }
 

 static av_unused int64_t flac_read_timestamp(AVFormatContext *s, int stream_index,
                                              int64_t *ppos, int64_t pos_limit)
 {
     AVPacket pkt, out_pkt;
     AVStream *st = s->streams[stream_index];

     AVCodecParserContext *parser;

     int ret;

     int64_t pts = AV_NOPTS_VALUE;

 
     if (avio_seek(s->pb, *ppos, SEEK_SET) < 0)
         return AV_NOPTS_VALUE;
 
     av_init_packet(&pkt);

     parser = av_parser_init(st->codec->codec_id);
     if (!parser){

         return AV_NOPTS_VALUE;
     }

     parser->flags |= PARSER_FLAG_USE_CODEC_TS;

 
     for (;;){
         ret = ff_raw_read_partial_packet(s, &pkt);
         if (ret < 0){
             if (ret == AVERROR(EAGAIN))
                 continue;
             else

                 break;

         }
         av_init_packet(&out_pkt);

         ret = av_parser_parse2(parser, st->codec,

                                &out_pkt.data, &out_pkt.size, pkt.data, pkt.size,
                                pkt.pts, pkt.dts, *ppos);
 

         av_free_packet(&pkt);

         if (out_pkt.size){
             int size = out_pkt.size;

             if (parser->pts != AV_NOPTS_VALUE){

                 // seeking may not have started from beginning of a frame
                 // calculate frame start position from next frame backwards

                 *ppos = parser->next_frame_offset - size;
                 pts = parser->pts;
                 break;

             }
         }
     }

     av_parser_close(parser);
     return pts;

 }
 

 AVInputFormat ff_flac_demuxer = {

     .name           = "flac",
     .long_name      = NULL_IF_CONFIG_SMALL("raw FLAC"),
     .read_probe     = flac_probe,
     .read_header    = flac_read_header,
     .read_packet    = ff_raw_read_partial_packet,

     .read_timestamp = flac_read_timestamp,

     .flags          = AVFMT_GENERIC_INDEX,
     .extensions     = "flac",

     .raw_codec_id   = AV_CODEC_ID_FLAC,

 };