/* * Musepack SV8 demuxer * Copyright (c) 2007 Konstantin Shishkov * * 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/bitstream.h" #include "libavcodec/unary.h" #include "avformat.h" /// Two-byte MPC tag #define MKMPCTAG(a, b) (a | (b << 8)) #define TAG_MPCK MKTAG('M','P','C','K') /// Reserved MPC tags enum MPCPacketTags{ TAG_STREAMHDR = MKMPCTAG('S','H'), TAG_STREAMEND = MKMPCTAG('S','E'), TAG_AUDIOPACKET = MKMPCTAG('A','P'), TAG_SEEKTBLOFF = MKMPCTAG('S','O'), TAG_SEEKTABLE = MKMPCTAG('S','T'), TAG_REPLAYGAIN = MKMPCTAG('R','G'), TAG_ENCINFO = MKMPCTAG('E','I'), }; static const int mpc8_rate[8] = { 44100, 48000, 37800, 32000, -1, -1, -1, -1 }; typedef struct { int ver; int frame; int64_t header_pos; int64_t samples; } MPCContext; static int mpc8_probe(AVProbeData *p) { if (AV_RL32(p->buf) == TAG_MPCK) return AVPROBE_SCORE_MAX; return 0; } static inline int64_t gb_get_v(GetBitContext *gb) { int64_t v = 0; int bits = 0; while(get_bits1(gb) && bits < 64-7){ v <<= 7; v |= get_bits(gb, 7); bits += 7; } v <<= 7; v |= get_bits(gb, 7); return v; } static void mpc8_get_chunk_header(ByteIOContext *pb, int *tag, int64_t *size) { int64_t pos; pos = url_ftell(pb); *tag = get_le16(pb); *size = ff_get_v(pb); *size -= url_ftell(pb) - pos; } static void mpc8_parse_seektable(AVFormatContext *s, int64_t off) { MPCContext *c = s->priv_data; int tag; int64_t size, pos, ppos[2]; uint8_t *buf; int i, t, seekd; GetBitContext gb; url_fseek(s->pb, off, SEEK_SET); mpc8_get_chunk_header(s->pb, &tag, &size); if(tag != TAG_SEEKTABLE){ av_log(s, AV_LOG_ERROR, "No seek table at given position\n"); return; } if(!(buf = av_malloc(size))) return; get_buffer(s->pb, buf, size); init_get_bits(&gb, buf, size * 8); size = gb_get_v(&gb); if(size > UINT_MAX/4 || size > c->samples/1152){ av_log(s, AV_LOG_ERROR, "Seek table is too big\n"); return; } seekd = get_bits(&gb, 4); for(i = 0; i < 2; i++){ pos = gb_get_v(&gb) + c->header_pos; ppos[1 - i] = pos; av_add_index_entry(s->streams[0], pos, i, 0, 0, AVINDEX_KEYFRAME); } for(; i < size; i++){ t = get_unary(&gb, 1, 33) << 12; t += get_bits(&gb, 12); if(t & 1) t = -(t & ~1); pos = (t >> 1) + ppos[0]*2 - ppos[1]; av_add_index_entry(s->streams[0], pos, i << seekd, 0, 0, AVINDEX_KEYFRAME); ppos[1] = ppos[0]; ppos[0] = pos; } av_free(buf); } static void mpc8_handle_chunk(AVFormatContext *s, int tag, int64_t chunk_pos, int64_t size) { ByteIOContext *pb = s->pb; int64_t pos, off; switch(tag){ case TAG_SEEKTBLOFF: pos = url_ftell(pb) + size; off = ff_get_v(pb); mpc8_parse_seektable(s, chunk_pos + off); url_fseek(pb, pos, SEEK_SET); break; default: url_fskip(pb, size); } } static int mpc8_read_header(AVFormatContext *s, AVFormatParameters *ap) { MPCContext *c = s->priv_data; ByteIOContext *pb = s->pb; AVStream *st; int tag = 0; int64_t size, pos; c->header_pos = url_ftell(pb); if(get_le32(pb) != TAG_MPCK){ av_log(s, AV_LOG_ERROR, "Not a Musepack8 file\n"); return -1; } while(!url_feof(pb)){ pos = url_ftell(pb); mpc8_get_chunk_header(pb, &tag, &size); if(tag == TAG_STREAMHDR) break; mpc8_handle_chunk(s, tag, pos, size); } if(tag != TAG_STREAMHDR){ av_log(s, AV_LOG_ERROR, "Stream header not found\n"); return -1; } pos = url_ftell(pb); url_fskip(pb, 4); //CRC c->ver = get_byte(pb); if(c->ver != 8){ av_log(s, AV_LOG_ERROR, "Unknown stream version %d\n", c->ver); return -1; } c->samples = ff_get_v(pb); ff_get_v(pb); //silence samples at the beginning st = av_new_stream(s, 0); if (!st) return AVERROR(ENOMEM); st->codec->codec_type = CODEC_TYPE_AUDIO; st->codec->codec_id = CODEC_ID_MUSEPACK8; st->codec->bits_per_coded_sample = 16; st->codec->extradata_size = 2; st->codec->extradata = av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE); get_buffer(pb, st->codec->extradata, st->codec->extradata_size); st->codec->channels = (st->codec->extradata[1] >> 4) + 1; st->codec->sample_rate = mpc8_rate[st->codec->extradata[0] >> 5]; av_set_pts_info(st, 32, 1152 << (st->codec->extradata[1]&3)*2, st->codec->sample_rate); st->duration = c->samples / (1152 << (st->codec->extradata[1]&3)*2); size -= url_ftell(pb) - pos; return 0; } static int mpc8_read_packet(AVFormatContext *s, AVPacket *pkt) { MPCContext *c = s->priv_data; int tag; int64_t pos, size; while(!url_feof(s->pb)){ pos = url_ftell(s->pb); mpc8_get_chunk_header(s->pb, &tag, &size); if(tag == TAG_AUDIOPACKET){ if(av_get_packet(s->pb, pkt, size) < 0) return AVERROR(ENOMEM); pkt->stream_index = 0; pkt->pts = c->frame; return 0; } if(tag == TAG_STREAMEND) return AVERROR(EIO); mpc8_handle_chunk(s, tag, pos, size); } return 0; } static int mpc8_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) { AVStream *st = s->streams[stream_index]; MPCContext *c = s->priv_data; int index = av_index_search_timestamp(st, timestamp, flags); if(index < 0) return -1; url_fseek(s->pb, st->index_entries[index].pos, SEEK_SET); c->frame = st->index_entries[index].timestamp; return 0; } AVInputFormat mpc8_demuxer = { "mpc8", NULL_IF_CONFIG_SMALL("Musepack SV8"), sizeof(MPCContext), mpc8_probe, mpc8_read_header, mpc8_read_packet, NULL, mpc8_read_seek, };