/* * 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 "libavutil/channel_layout.h"#include "libavutil/mem.h"#include "libavcodec/avcodec.h"#include "libavcodec/bytestream.h"#include "libavcodec/flac.h"#include "avformat.h"#include "demux.h"#include "flac_picture.h"#include "internal.h"#include "rawdec.h"#include "oggdec.h"#include "replaygain.h" #define SEEKPOINT_SIZE 18 typedef struct FLACDecContext {    FFRawDemuxerContext rawctx;    int found_seektable;     AVCodecContext *parser_dec;} FLACDecContext; static void reset_index_position(int64_t metadata_head_size, AVStream *st){    FFStream *const sti = ffstream(st);    /* the real seek index offset should be the size of metadata blocks with the offset in the frame blocks */    for (int i = 0; i < sti->nb_index_entries; i++)        sti->index_entries[i].pos += metadata_head_size;} static const uint16_t sr_table[16] = {    0, 1764, 3528, 3840, 160, 320, 441, 480, 640, 882, 960, 1920, 0, 0, 0, 0}; 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;    uint32_t marker;    FLACDecContext *flac = s->priv_data;    AVStream *st = avformat_new_stream(s, NULL);    if (!st)        return AVERROR(ENOMEM);    st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;    st->codecpar->codec_id = AV_CODEC_ID_FLAC;    ffstream(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 */    marker = avio_rl32(s->pb);    if (marker != MKTAG('f','L','a','C')) {        const int sample_rate = 50 * sr_table[(marker >> 16) & 0xF];        if (sample_rate)            avpriv_set_pts_info(st, 64, 1, sample_rate);        avio_seek(s->pb, -4, SEEK_CUR);        return 0;    }     /* process metadata blocks */    while (!avio_feof(s->pb) && !metadata_last) {        if (avio_read(s->pb, header, 4) != 4)            return AVERROR_INVALIDDATA;        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:        case FLAC_METADATA_TYPE_SEEKTABLE:            buffer = av_mallocz(metadata_size + AV_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->codecpar->extradata      = buffer;            st->codecpar->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->codecpar->extradata + 10) >> 4;            samples    = (AV_RB64(st->codecpar->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, 1);            av_freep(&buffer);            if (ret < 0) {                av_log(s, AV_LOG_ERROR, "Error parsing attached picture.\n");                return ret;            }        } else if (metadata_type == FLAC_METADATA_TYPE_SEEKTABLE) {            const uint8_t *seekpoint = buffer;            int i, seek_point_count = metadata_size/SEEKPOINT_SIZE;            flac->found_seektable = 1;            if ((s->flags&AVFMT_FLAG_FAST_SEEK)) {                for(i=0; i<seek_point_count; i++) {                    int64_t timestamp = bytestream_get_be64(&seekpoint);                    int64_t pos = bytestream_get_be64(&seekpoint);                    /* skip number of samples */                    bytestream_get_be16(&seekpoint);                    av_add_index_entry(st, pos, timestamp, 0, 0, AVINDEX_KEYFRAME);                }            }            av_freep(&buffer);        }        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 {                        av_channel_layout_from_mask(&st->codecpar->ch_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;     reset_index_position(avio_tell(s->pb), st);    return 0; fail:    av_free(buffer);    return ret;} static int raw_flac_probe(const AVProbeData *p){    if ((p->buf[2] & 0xF0) == 0)    // blocksize code invalid        return 0;    if ((p->buf[2] & 0x0F) == 0x0F) // sample rate code invalid        return 0;    if ((p->buf[3] & 0xF0) >= FLAC_MAX_CHANNELS + FLAC_CHMODE_MID_SIDE << 4)        // channel mode invalid        return 0;    if ((p->buf[3] & 0x06) == 0x06) // bits per sample code invalid        return 0;    if ((p->buf[3] & 0x01) == 0x01) // reserved bit set        return 0;    return AVPROBE_SCORE_EXTENSION / 4 + 1;} static int flac_probe(const AVProbeData *p){    if ((AV_RB16(p->buf) & 0xFFFE) == 0xFFF8)        return raw_flac_probe(p);     /* file header + metadata header + checked bytes of streaminfo */    if (p->buf_size >= 4 + 4 + 13) {        int type           = p->buf[4] & 0x7f;        int size           = AV_RB24(p->buf + 5);        int min_block_size = AV_RB16(p->buf + 8);        int max_block_size = AV_RB16(p->buf + 10);        int sample_rate    = AV_RB24(p->buf + 18) >> 4;         if (memcmp(p->buf, "fLaC", 4))            return 0;        if (type == FLAC_METADATA_TYPE_STREAMINFO &&            size == FLAC_STREAMINFO_SIZE          &&            min_block_size >= 16                  &&            max_block_size >= min_block_size      &&            sample_rate && sample_rate <= 655350)            return AVPROBE_SCORE_MAX;        return AVPROBE_SCORE_EXTENSION;    }     return 0;} static av_unused int64_t flac_read_timestamp(AVFormatContext *s, int stream_index,                                             int64_t *ppos, int64_t pos_limit){    FLACDecContext *flac = s->priv_data;    FFFormatContext *const si = ffformatcontext(s);    AVPacket *const pkt = si->parse_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;     if (!flac->parser_dec) {        flac->parser_dec = avcodec_alloc_context3(NULL);        if (!flac->parser_dec)            return AV_NOPTS_VALUE;         ret = avcodec_parameters_to_context(flac->parser_dec, st->codecpar);        if (ret < 0)            return ret;    }     parser = av_parser_init(st->codecpar->codec_id);    if (!parser)        return AV_NOPTS_VALUE;    parser->flags |= PARSER_FLAG_USE_CODEC_TS;     for (;;){        uint8_t *data;        int size;         ret = ff_raw_read_partial_packet(s, pkt);        if (ret < 0){            if (ret == AVERROR(EAGAIN))                continue;            else {                av_packet_unref(pkt);                av_assert1(!pkt->size);            }        }        av_parser_parse2(parser, flac->parser_dec,                         &data, &size, pkt->data, pkt->size,                         pkt->pts, pkt->dts, *ppos);         av_packet_unref(pkt);        if (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;            }        } else if (ret < 0)            break;    }    av_parser_close(parser);    return pts;} static int flac_close(AVFormatContext *s){    FLACDecContext *flac = s->priv_data;     avcodec_free_context(&flac->parser_dec);     return 0;} static int flac_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) {    AVStream *const st  = s->streams[0];    FFStream *const sti = ffstream(st);    int index;    int64_t pos;    AVIndexEntry e;    FLACDecContext *flac = s->priv_data;     if (!flac->found_seektable || !(s->flags&AVFMT_FLAG_FAST_SEEK)) {        return -1;    }     index = av_index_search_timestamp(st, timestamp, flags);    if (index < 0 || index >= sti->nb_index_entries)        return -1;     e   = sti->index_entries[index];    pos = avio_seek(s->pb, e.pos, SEEK_SET);    if (pos >= 0) {        return 0;    }    return -1;} const FFInputFormat ff_flac_demuxer = {    .p.name         = "flac",    .p.long_name    = NULL_IF_CONFIG_SMALL("raw FLAC"),    .p.flags        = AVFMT_GENERIC_INDEX,    .p.extensions   = "flac",    .p.priv_class   = &ff_raw_demuxer_class,    .read_probe     = flac_probe,    .read_header    = flac_read_header,    .read_close     = flac_close,    .read_packet    = ff_raw_read_partial_packet,    .read_seek      = flac_seek,    .read_timestamp = flac_read_timestamp,    .raw_codec_id   = AV_CODEC_ID_FLAC,    .priv_data_size = sizeof(FLACDecContext),};