static int dca_parse_params(const uint8_t *buf, int buf_size, int *duration,
                            int *sample_rate, int *framesize)
{
    GetBitContext gb;
    uint8_t hdr[12 + AV_INPUT_BUFFER_PADDING_SIZE] = { 0 };
    int ret, sample_blocks, sr_code;

    if (buf_size < 12)
        return AVERROR_INVALIDDATA;

    if ((ret = avpriv_dca_convert_bitstream(buf, 12, hdr, 12)) < 0)
        return ret;

    init_get_bits(&gb, hdr, 96);

    skip_bits_long(&gb, 39);
    sample_blocks = get_bits(&gb, 7) + 1;
    if (sample_blocks < 8)
        return AVERROR_INVALIDDATA;
    *duration = 256 * (sample_blocks / 8);

    *framesize = get_bits(&gb, 14) + 1;
    if (*framesize < 95)
        return AVERROR_INVALIDDATA;

    skip_bits(&gb, 6);
    sr_code      = get_bits(&gb, 4);
    *sample_rate = avpriv_dca_sample_rates[sr_code];
    if (*sample_rate == 0)
        return AVERROR_INVALIDDATA;

    return 0;
}
Example #2
0
static int convert_bitstream(const uint8_t *src, int src_size, uint8_t *dst, int max_size)
{
    switch (AV_RB32(src)) {
    case DCA_SYNCWORD_CORE_BE:
    case DCA_SYNCWORD_SUBSTREAM:
        memcpy(dst, src, src_size);
        return src_size;
    case DCA_SYNCWORD_CORE_LE:
    case DCA_SYNCWORD_CORE_14B_BE:
    case DCA_SYNCWORD_CORE_14B_LE:
        return avpriv_dca_convert_bitstream(src, src_size, dst, max_size);
    default:
        return AVERROR_INVALIDDATA;
    }
}
Example #3
0
File: dtsdec.c Project: 63n/FFmpeg
static int dts_probe(AVProbeData *p)
{
    const uint8_t *buf, *bufp;
    uint32_t state = -1;
    int markers[4*16] = {0};
    int sum, max, i;
    int64_t diff = 0;
    uint8_t hdr[12 + FF_INPUT_BUFFER_PADDING_SIZE] = { 0 };

    buf = p->buf + FFMIN(4096, p->buf_size);

    for(; buf < (p->buf+p->buf_size)-2; buf+=2) {
        int marker, sample_blocks, sample_rate, sr_code, framesize;
        int lfe;
        GetBitContext gb;

        bufp = buf;
        state = (state << 16) | bytestream_get_be16(&bufp);

        if (buf - p->buf >= 4)
            diff += FFABS(((int16_t)AV_RL16(buf)) - (int16_t)AV_RL16(buf-4));

        /* regular bitstream */
        if (state == DCA_SYNCWORD_CORE_BE)
            marker = 0;
        else if (state == DCA_SYNCWORD_CORE_LE)
            marker = 1;

        /* 14 bits big-endian bitstream */
        else if (state == DCA_SYNCWORD_CORE_14B_BE &&
                 (bytestream_get_be16(&bufp) & 0xFFF0) == 0x07F0)
            marker = 2;

        /* 14 bits little-endian bitstream */
        else if (state == DCA_SYNCWORD_CORE_14B_LE &&
                 (bytestream_get_be16(&bufp) & 0xF0FF) == 0xF007)
            marker = 3;
        else
            continue;

        if (avpriv_dca_convert_bitstream(buf-2, 12, hdr, 12) < 0)
            continue;

        init_get_bits(&gb, hdr, 96);
        skip_bits_long(&gb, 39);

        sample_blocks = get_bits(&gb, 7) + 1;
        if (sample_blocks < 8)
            continue;

        framesize = get_bits(&gb, 14) + 1;
        if (framesize < 95)
            continue;

        skip_bits(&gb, 6);
        sr_code = get_bits(&gb, 4);
        sample_rate = avpriv_dca_sample_rates[sr_code];
        if (sample_rate == 0)
            continue;

        get_bits(&gb, 5);
        if (get_bits(&gb, 1))
            continue;

        skip_bits_long(&gb, 9);
        lfe = get_bits(&gb, 2);
        if (lfe > 2)
            continue;

        marker += 4* sr_code;

        markers[marker] ++;
    }

    sum = max = 0;
    for (i=0; i<FF_ARRAY_ELEMS(markers); i++) {
        sum += markers[i];
        if (markers[max] < markers[i])
            max = i;
    }

    if (markers[max] > 3 && p->buf_size / markers[max] < 32*1024 &&
        markers[max] * 4 > sum * 3 &&
        diff / p->buf_size > 200)
        return AVPROBE_SCORE_EXTENSION + 1;

    return 0;
}
Example #4
0
static int dcadec_decode_frame(AVCodecContext *avctx, void *data,
                               int *got_frame_ptr, AVPacket *avpkt)
{
    DCAContext *s = avctx->priv_data;
    AVFrame *frame = data;
    uint8_t *input = avpkt->data;
    int input_size = avpkt->size;
    int i, ret, prev_packet = s->packet;
    uint32_t mrk;

    if (input_size < MIN_PACKET_SIZE || input_size > MAX_PACKET_SIZE) {
        av_log(avctx, AV_LOG_ERROR, "Invalid packet size\n");
        return AVERROR_INVALIDDATA;
    }

    // Convert input to BE format
    mrk = AV_RB32(input);
    if (mrk != DCA_SYNCWORD_CORE_BE && mrk != DCA_SYNCWORD_SUBSTREAM) {
        av_fast_padded_malloc(&s->buffer, &s->buffer_size, input_size);
        if (!s->buffer)
            return AVERROR(ENOMEM);

        for (i = 0, ret = AVERROR_INVALIDDATA; i < input_size - MIN_PACKET_SIZE + 1 && ret < 0; i++)
            ret = avpriv_dca_convert_bitstream(input + i, input_size - i, s->buffer, s->buffer_size);

        if (ret < 0) {
            av_log(avctx, AV_LOG_ERROR, "Not a valid DCA frame\n");
            return ret;
        }

        input      = s->buffer;
        input_size = ret;
    }

    s->packet = 0;

    // Parse backward compatible core sub-stream
    if (AV_RB32(input) == DCA_SYNCWORD_CORE_BE) {
        int frame_size;

        if ((ret = ff_dca_core_parse(&s->core, input, input_size)) < 0)
            return ret;

        s->packet |= DCA_PACKET_CORE;

        // EXXS data must be aligned on 4-byte boundary
        frame_size = FFALIGN(s->core.frame_size, 4);
        if (input_size - 4 > frame_size) {
            input      += frame_size;
            input_size -= frame_size;
        }
    }

    if (!s->core_only) {
        DCAExssAsset *asset = NULL;

        // Parse extension sub-stream (EXSS)
        if (AV_RB32(input) == DCA_SYNCWORD_SUBSTREAM) {
            if ((ret = ff_dca_exss_parse(&s->exss, input, input_size)) < 0) {
                if (avctx->err_recognition & AV_EF_EXPLODE)
                    return ret;
            } else {
                s->packet |= DCA_PACKET_EXSS;
                asset = &s->exss.assets[0];
            }
        }

        // Parse XLL component in EXSS
        if (asset && (asset->extension_mask & DCA_EXSS_XLL)) {
            if ((ret = ff_dca_xll_parse(&s->xll, input, asset)) < 0) {
                // Conceal XLL synchronization error
                if (ret == AVERROR(EAGAIN)
                    && (prev_packet & DCA_PACKET_XLL)
                    && (s->packet & DCA_PACKET_CORE))
                    s->packet |= DCA_PACKET_XLL | DCA_PACKET_RECOVERY;
                else if (ret == AVERROR(ENOMEM) || (avctx->err_recognition & AV_EF_EXPLODE))
                    return ret;
            } else {
                s->packet |= DCA_PACKET_XLL;
            }
        }

        // Parse LBR component in EXSS
        if (asset && (asset->extension_mask & DCA_EXSS_LBR)) {
            if ((ret = ff_dca_lbr_parse(&s->lbr, input, asset)) < 0) {
                if (ret == AVERROR(ENOMEM) || (avctx->err_recognition & AV_EF_EXPLODE))
                    return ret;
            } else {
                s->packet |= DCA_PACKET_LBR;
            }
        }

        // Parse core extensions in EXSS or backward compatible core sub-stream
        if ((s->packet & DCA_PACKET_CORE)
            && (ret = ff_dca_core_parse_exss(&s->core, input, asset)) < 0)
            return ret;
    }

    // Filter the frame
    if (s->packet & DCA_PACKET_LBR) {
        if ((ret = ff_dca_lbr_filter_frame(&s->lbr, frame)) < 0)
            return ret;
    } else if (s->packet & DCA_PACKET_XLL) {
        if (s->packet & DCA_PACKET_CORE) {
            int x96_synth = -1;

            // Enable X96 synthesis if needed
            if (s->xll.chset[0].freq == 96000 && s->core.sample_rate == 48000)
                x96_synth = 1;

            if ((ret = ff_dca_core_filter_fixed(&s->core, x96_synth)) < 0)
                return ret;

            // Force lossy downmixed output on the first core frame filtered.
            // This prevents audible clicks when seeking and is consistent with
            // what reference decoder does when there are multiple channel sets.
            if (!(prev_packet & DCA_PACKET_RESIDUAL) && s->xll.nreschsets > 0
                && s->xll.nchsets > 1) {
                av_log(avctx, AV_LOG_VERBOSE, "Forcing XLL recovery mode\n");
                s->packet |= DCA_PACKET_RECOVERY;
            }

            // Set 'residual ok' flag for the next frame
            s->packet |= DCA_PACKET_RESIDUAL;
        }

        if ((ret = ff_dca_xll_filter_frame(&s->xll, frame)) < 0) {
            // Fall back to core unless hard error
            if (!(s->packet & DCA_PACKET_CORE))
                return ret;
            if (ret != AVERROR_INVALIDDATA || (avctx->err_recognition & AV_EF_EXPLODE))
                return ret;
            if ((ret = ff_dca_core_filter_frame(&s->core, frame)) < 0)
                return ret;
        }
    } else if (s->packet & DCA_PACKET_CORE) {
        if ((ret = ff_dca_core_filter_frame(&s->core, frame)) < 0)
            return ret;
        if (s->core.filter_mode & DCA_FILTER_MODE_FIXED)
            s->packet |= DCA_PACKET_RESIDUAL;
    } else {
        av_log(avctx, AV_LOG_ERROR, "No valid DCA sub-stream found\n");
        if (s->core_only)
            av_log(avctx, AV_LOG_WARNING, "Consider disabling 'core_only' option\n");
        return AVERROR_INVALIDDATA;
    }

    *got_frame_ptr = 1;

    return avpkt->size;
}