Exemplo n.º 1
0
/** Uncompress one block (20 bytes -> 160*2 bytes). */
static int ra144_decode_frame(AVCodecContext * avctx, void *vdata,
                              int *data_size, AVPacket *avpkt)
{
    const uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size;
    static const uint8_t sizes[10] = {6, 5, 5, 4, 4, 3, 3, 3, 3, 2};
    unsigned int refl_rms[4];    // RMS of the reflection coefficients
    uint16_t block_coefs[4][10]; // LPC coefficients of each sub-block
    unsigned int lpc_refl[10];   // LPC reflection coefficients of the frame
    int i, j;
    int16_t *data = vdata;
    unsigned int energy;

    RA144Context *ractx = avctx->priv_data;
    GetBitContext gb;

    if (*data_size < 2*160)
        return -1;

    if(buf_size < 20) {
        av_log(avctx, AV_LOG_ERROR,
               "Frame too small (%d bytes). Truncated file?\n", buf_size);
        *data_size = 0;
        return buf_size;
    }
    init_get_bits(&gb, buf, 20 * 8);

    for (i=0; i<10; i++)
        lpc_refl[i] = ff_lpc_refl_cb[i][get_bits(&gb, sizes[i])];

    ff_eval_coefs(ractx->lpc_coef[0], lpc_refl);
    ractx->lpc_refl_rms[0] = ff_rms(lpc_refl);

    energy = ff_energy_tab[get_bits(&gb, 5)];

    refl_rms[0] = ff_interp(ractx, block_coefs[0], 1, 1, ractx->old_energy);
    refl_rms[1] = ff_interp(ractx, block_coefs[1], 2,
                            energy <= ractx->old_energy,
                            ff_t_sqrt(energy*ractx->old_energy) >> 12);
    refl_rms[2] = ff_interp(ractx, block_coefs[2], 3, 0, energy);
    refl_rms[3] = ff_rescale_rms(ractx->lpc_refl_rms[0], energy);

    ff_int_to_int16(block_coefs[3], ractx->lpc_coef[0]);

    for (i=0; i < 4; i++) {
        do_output_subblock(ractx, block_coefs[i], refl_rms[i], &gb);

        for (j=0; j < BLOCKSIZE; j++)
            *data++ = av_clip_int16(ractx->curr_sblock[j + 10] << 2);
    }

    ractx->old_energy = energy;
    ractx->lpc_refl_rms[1] = ractx->lpc_refl_rms[0];

    FFSWAP(unsigned int *, ractx->lpc_coef[0], ractx->lpc_coef[1]);

    *data_size = 2*160;
    return 20;
}
Exemplo n.º 2
0
/** Uncompress one block (20 bytes -> 160*2 bytes). */
static int ra144_decode_frame(AVCodecContext * avctx, void *data,
                              int *got_frame_ptr, AVPacket *avpkt)
{
    AVFrame *frame     = data;
    const uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size;
    static const uint8_t sizes[LPC_ORDER] = {6, 5, 5, 4, 4, 3, 3, 3, 3, 2};
    unsigned int refl_rms[NBLOCKS];           // RMS of the reflection coefficients
    int16_t block_coefs[NBLOCKS][LPC_ORDER];  // LPC coefficients of each sub-block
    unsigned int lpc_refl[LPC_ORDER];         // LPC reflection coefficients of the frame
    int i, j;
    int ret;
    int16_t *samples;
    unsigned int energy;

    RA144Context *ractx = avctx->priv_data;
    GetBitContext gb;

    if (buf_size < FRAME_SIZE) {
        av_log(avctx, AV_LOG_ERROR,
               "Frame too small (%d bytes). Truncated file?\n", buf_size);
        *got_frame_ptr = 0;
        return AVERROR_INVALIDDATA;
    }

    /* get output buffer */
    frame->nb_samples = NBLOCKS * BLOCKSIZE;
    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
        return ret;
    samples = (int16_t *)frame->data[0];

    init_get_bits8(&gb, buf, FRAME_SIZE);

    for (i = 0; i < LPC_ORDER; i++)
        lpc_refl[i] = ff_lpc_refl_cb[i][get_bits(&gb, sizes[i])];

    ff_eval_coefs(ractx->lpc_coef[0], lpc_refl);
    ractx->lpc_refl_rms[0] = ff_rms(lpc_refl);

    energy = ff_energy_tab[get_bits(&gb, 5)];

    refl_rms[0] = ff_interp(ractx, block_coefs[0], 1, 1, ractx->old_energy);
    refl_rms[1] = ff_interp(ractx, block_coefs[1], 2,
                            energy <= ractx->old_energy,
                            ff_t_sqrt(energy*ractx->old_energy) >> 12);
    refl_rms[2] = ff_interp(ractx, block_coefs[2], 3, 0, energy);
    refl_rms[3] = ff_rescale_rms(ractx->lpc_refl_rms[0], energy);

    ff_int_to_int16(block_coefs[3], ractx->lpc_coef[0]);

    for (i=0; i < NBLOCKS; i++) {
        do_output_subblock(ractx, block_coefs[i], refl_rms[i], &gb);

        for (j=0; j < BLOCKSIZE; j++)
            *samples++ = av_clip_int16(ractx->curr_sblock[j + 10] << 2);
    }

    ractx->old_energy = energy;
    ractx->lpc_refl_rms[1] = ractx->lpc_refl_rms[0];

    FFSWAP(unsigned int *, ractx->lpc_coef[0], ractx->lpc_coef[1]);

    *got_frame_ptr = 1;

    return FRAME_SIZE;
}