tta.c

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/*
 * TTA demuxer
 * Copyright (c) 2006 Alex Beregszaszi
 *
 * 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/crc.h"
#include "libavutil/dict.h"
#include "libavutil/intreadwrite.h"
 
#include "apetag.h"
#include "avformat.h"
#include "avio_internal.h"
#include "demux.h"
#include "internal.h"
#include "id3v1.h"
 
typedef struct TTAContext {
    int totalframes, currentframe;
    int frame_size;
    int last_frame_size;
} TTAContext;
 
static int tta_probe(const AVProbeData *p)
{
    if (AV_RL32(&p->buf[0]) == MKTAG('T', 'T', 'A', '1') &&
        (AV_RL16(&p->buf[4]) == 1 || AV_RL16(&p->buf[4]) == 2) &&
        AV_RL16(&p->buf[6]) > 0 &&
        AV_RL16(&p->buf[8]) > 0 &&
        AV_RL32(&p->buf[10]) > 0)
        return AVPROBE_SCORE_EXTENSION + 30;
    return 0;
}
 
static int tta_read_header(AVFormatContext *s)
{
    TTAContext *c = s->priv_data;
    AVStream *st;
    int64_t framepos;
    uint8_t header[22];
 
    ff_id3v1_read(s);
 
    int ret = ffio_read_size(s->pb, header, sizeof(header));
    if (ret < 0)
        return ret;
 
    if (AV_RL32(header) != MKTAG('T', 'T', 'A', '1'))
        return AVERROR_INVALIDDATA;
 
    int channels   = AV_RL16(header +  6);
    int bps        = AV_RL16(header +  8);
    int samplerate = AV_RL32(header + 10);
    if(samplerate <= 0 || samplerate > 1000000){
        av_log(s, AV_LOG_ERROR, "nonsense samplerate\n");
        return AVERROR_INVALIDDATA;
    }
 
    uint32_t nb_samples = AV_RL32(header + 14);
    if (!nb_samples) {
        av_log(s, AV_LOG_ERROR, "invalid number of samples\n");
        return AVERROR_INVALIDDATA;
    }
 
    uint32_t crc = av_crc(av_crc_get_table(AV_CRC_32_IEEE_LE), UINT32_MAX, header, 18) ^ UINT32_MAX;
    if (crc != AV_RL32(header + 18) && s->error_recognition & AV_EF_CRCCHECK) {
        av_log(s, AV_LOG_ERROR, "Header CRC error\n");
        return AVERROR_INVALIDDATA;
    }
 
    c->frame_size      = samplerate * 256 / 245;
    c->last_frame_size = nb_samples % c->frame_size;
    if (!c->last_frame_size)
        c->last_frame_size = c->frame_size;
    c->totalframes = nb_samples / c->frame_size + (c->last_frame_size < c->frame_size);
    c->currentframe = 0;
 
    if(c->totalframes >= (INT_MAX - 4)/sizeof(uint32_t) || c->totalframes <= 0){
        av_log(s, AV_LOG_ERROR, "totalframes %d invalid\n", c->totalframes);
        return AVERROR_INVALIDDATA;
    }
 
    st = avformat_new_stream(s, NULL);
    if (!st)
        return AVERROR(ENOMEM);
 
    avpriv_set_pts_info(st, 64, 1, samplerate);
    st->start_time = 0;
    st->duration = nb_samples;
 
    ret = ff_alloc_extradata(st->codecpar, sizeof(header));
    if (ret < 0)
        return ret;
    memcpy(st->codecpar->extradata, header, sizeof(header));
 
    framepos = avio_tell(s->pb);
    if (framepos < 0)
        return framepos;
    framepos += 4 * c->totalframes + 4;
 
    ffio_init_checksum(s->pb, ff_crcEDB88320_update, UINT32_MAX);
    for (int i = 0; i < c->totalframes; i++) {
        uint32_t size = avio_rl32(s->pb);
        int r;
        if (avio_feof(s->pb))
            return AVERROR_INVALIDDATA;
        if ((r = av_add_index_entry(st, framepos, i * (int64_t)c->frame_size, size, 0,
                                    AVINDEX_KEYFRAME)) < 0)
            return r;
        framepos += size;
    }
    crc = ffio_get_checksum(s->pb) ^ UINT32_MAX;
    if (crc != avio_rl32(s->pb) && s->error_recognition & AV_EF_CRCCHECK) {
        av_log(s, AV_LOG_ERROR, "Seek table CRC error\n");
        return AVERROR_INVALIDDATA;
    }
 
    st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
    st->codecpar->codec_id = AV_CODEC_ID_TTA;
    st->codecpar->ch_layout.nb_channels = channels;
    st->codecpar->sample_rate = samplerate;
    st->codecpar->bits_per_coded_sample = bps;
 
    if (s->pb->seekable & AVIO_SEEKABLE_NORMAL) {
        int64_t pos = avio_tell(s->pb);
        ff_ape_parse_tag(s);
        avio_seek(s->pb, pos, SEEK_SET);
    }
 
    return 0;
}
 
static int tta_read_packet(AVFormatContext *s, AVPacket *pkt)
{
    TTAContext *c = s->priv_data;
    AVStream *st = s->streams[0];
    FFStream *const sti = ffstream(st);
    int size, ret;
 
    // FIXME!
    if (c->currentframe >= c->totalframes)
        return AVERROR_EOF;
 
    if (sti->nb_index_entries < c->totalframes) {
        av_log(s, AV_LOG_ERROR, "Index entry disappeared\n");
        return AVERROR_INVALIDDATA;
    }
 
    size = sti->index_entries[c->currentframe].size;
 
    ret = av_get_packet(s->pb, pkt, size);
    pkt->dts = sti->index_entries[c->currentframe++].timestamp;
    pkt->duration = c->currentframe == c->totalframes ? c->last_frame_size :
                                                        c->frame_size;
    return ret;
}
 
static int tta_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
{
    TTAContext *c = s->priv_data;
    AVStream *st = s->streams[stream_index];
    int index = av_index_search_timestamp(st, timestamp, flags);
    if (index < 0)
        return -1;
    if (avio_seek(s->pb, ffstream(st)->index_entries[index].pos, SEEK_SET) < 0)
        return -1;
 
    c->currentframe = index;
 
    return 0;
}
 
const FFInputFormat ff_tta_demuxer = {
    .p.name         = "tta",
    .p.long_name    = NULL_IF_CONFIG_SMALL("TTA (True Audio)"),
    .p.extensions   = "tta",
    .priv_data_size = sizeof(TTAContext),
    .flags_internal = FF_INFMT_FLAG_ID3V2_AUTO,
    .read_probe     = tta_probe,
    .read_header    = tta_read_header,
    .read_packet    = tta_read_packet,
    .read_seek      = tta_read_seek,
};