vmdav.c

tcpmp播放器的flv插件

                    }
                } while (ofs < frame_width);
                if (ofs > frame_width) {
                    av_log(s->avctx, AV_LOG_ERROR, "VMD video: offset > width (%d > %d)\n",
                        ofs, frame_width);
                }
                dp += s->frame.linesize[0];
                pp += s->prev_frame.linesize[0];
            }
            break;
        }
    }
}

static int vmdvideo_decode_init(AVCodecContext *avctx)
{
    VmdVideoContext *s = (VmdVideoContext *)avctx->priv_data;
    int i;
    unsigned int *palette32;
    int palette_index = 0;
    unsigned char r, g, b;
    unsigned char *vmd_header;
    unsigned char *raw_palette;

    s->avctx = avctx;
    avctx->pix_fmt = PIX_FMT_PAL8;
    avctx->has_b_frames = 0;
    dsputil_init(&s->dsp, avctx);

    /* make sure the VMD header made it */
    if (s->avctx->extradata_size != VMD_HEADER_SIZE) {
        av_log(s->avctx, AV_LOG_ERROR, "VMD video: expected extradata size of %d\n", 
            VMD_HEADER_SIZE);
        return -1;
    }
    vmd_header = (unsigned char *)avctx->extradata;

    s->unpack_buffer_size = LE_32(&vmd_header[800]);
    s->unpack_buffer = av_malloc(s->unpack_buffer_size);
    if (!s->unpack_buffer)
        return -1;

    /* load up the initial palette */
    raw_palette = &vmd_header[28];
    palette32 = (unsigned int *)s->palette;
    for (i = 0; i < PALETTE_COUNT; i++) {
        r = raw_palette[palette_index++] * 4;
        g = raw_palette[palette_index++] * 4;
        b = raw_palette[palette_index++] * 4;
        palette32[i] = (r << 16) | (g << 8) | (b);
    }

    s->frame.data[0] = s->prev_frame.data[0] = NULL;

    return 0;
}

static int vmdvideo_decode_frame(AVCodecContext *avctx,
                                 void *data, int *data_size,
                                 uint8_t *buf, int buf_size)
{
    VmdVideoContext *s = (VmdVideoContext *)avctx->priv_data;

    s->buf = buf;
    s->size = buf_size;

    if (buf_size < 16)
        return buf_size;

    s->frame.reference = 1;
    if (avctx->get_buffer(avctx, &s->frame)) {
        av_log(s->avctx, AV_LOG_ERROR, "VMD Video: get_buffer() failed\n");
        return -1;
    }

    vmd_decode(s);

    /* make the palette available on the way out */
    memcpy(s->frame.data[1], s->palette, PALETTE_COUNT * 4);

    if (s->prev_frame.data[0])
        avctx->release_buffer(avctx, &s->prev_frame);

    /* shuffle frames */
    s->prev_frame = s->frame;

    *data_size = sizeof(AVFrame);
    *(AVFrame*)data = s->frame;

    /* report that the buffer was completely consumed */
    return buf_size;
}

static int vmdvideo_decode_end(AVCodecContext *avctx)
{
    VmdVideoContext *s = (VmdVideoContext *)avctx->priv_data;

    if (s->prev_frame.data[0])
        avctx->release_buffer(avctx, &s->prev_frame);
    av_free(s->unpack_buffer);

    return 0;
}


/*
 * Audio Decoder
 */

typedef struct VmdAudioContext {
    AVCodecContext *avctx;
    int channels;
    int bits;
    int block_align;
    unsigned char steps8[16];
    unsigned short steps16[16];
    unsigned short steps128[256];
    short predictors[2];
} VmdAudioContext;

static int vmdaudio_decode_init(AVCodecContext *avctx)
{
    VmdAudioContext *s = (VmdAudioContext *)avctx->priv_data;
    int i;

    s->avctx = avctx;
    s->channels = avctx->channels;
    s->bits = avctx->bits_per_sample;
    s->block_align = avctx->block_align;

    av_log(s->avctx, AV_LOG_DEBUG, "%d channels, %d bits/sample, block align = %d, sample rate = %d\n",
	    s->channels, s->bits, s->block_align, avctx->sample_rate);

    /* set up the steps8 and steps16 tables */
    for (i = 0; i < 8; i++) {
        if (i < 4)
            s->steps8[i] = i;
        else
            s->steps8[i] = s->steps8[i - 1] + i - 1;

        if (i == 0)
            s->steps16[i] = 0;
        else if (i == 1)
            s->steps16[i] = 4;
        else if (i == 2)
            s->steps16[i] = 16;
        else
            s->steps16[i] = 1 << (i + 4);
    }

    /* set up the step128 table */
    s->steps128[0] = 0;
    s->steps128[1] = 8;
    for (i = 0x02; i <= 0x20; i++)
        s->steps128[i] = (i - 1) << 4;
    for (i = 0x21; i <= 0x60; i++)
        s->steps128[i] = (i + 0x1F) << 3;
    for (i = 0x61; i <= 0x70; i++)
        s->steps128[i] = (i - 0x51) << 6;
    for (i = 0x71; i <= 0x78; i++)
        s->steps128[i] = (i - 0x69) << 8;
    for (i = 0x79; i <= 0x7D; i++)
        s->steps128[i] = (i - 0x75) << 10;
    s->steps128[0x7E] = 0x3000;
    s->steps128[0x7F] = 0x4000;

    /* set up the negative half of each table */
    for (i = 0; i < 8; i++) {
        s->steps8[i + 8] = -s->steps8[i];
        s->steps16[i + 8] = -s->steps16[i];
    }
    for (i = 0; i < 128; i++)
      s->steps128[i + 128] = -s->steps128[i];

    return 0;
}

static void vmdaudio_decode_audio(VmdAudioContext *s, unsigned char *data,
    uint8_t *buf, int ratio) {

}

static int vmdaudio_loadsound(VmdAudioContext *s, unsigned char *data,
    uint8_t *buf, int silence)
{
    int bytes_decoded = 0;
    int i;

    if (silence)
	av_log(s->avctx, AV_LOG_INFO, "silent block!\n");
    if (s->channels == 2) {

        /* stereo handling */
        if ((s->block_align & 0x01) == 0) {
            if (silence)
                memset(data, 0, s->block_align * 2);
            else
                vmdaudio_decode_audio(s, data, buf, 1);
        } else {
            if (silence)
                memset(data, 0, s->block_align * 2);
            else
                vmdaudio_decode_audio(s, data, buf, 1);
        }
    } else {

        /* mono handling */
        if (silence) {
            if (s->bits == 16) {
                memset(data, 0, s->block_align * 2);
                bytes_decoded = s->block_align * 2;
            } else {
//                memset(data, 0x00, s->block_align);
//                bytes_decoded = s->block_align;
memset(data, 0x00, s->block_align * 2);
bytes_decoded = s->block_align * 2;
            }
        } else {
            /* copy the data but convert it to signed */
            for (i = 0; i < s->block_align; i++)
                data[i * 2 + 1] = buf[i] + 0x80;
            bytes_decoded = s->block_align * 2;
        }
    }

    return bytes_decoded;
}

static int vmdaudio_decode_frame(AVCodecContext *avctx,
                                 void *data, int *data_size,
                                 uint8_t *buf, int buf_size)
{
    VmdAudioContext *s = (VmdAudioContext *)avctx->priv_data;
    unsigned int sound_flags;
    unsigned char *output_samples = (unsigned char *)data;

    /* point to the start of the encoded data */
    unsigned char *p = buf + 16;
    unsigned char *p_end = buf + buf_size;

    if (buf_size < 16)
        return buf_size;

    if (buf[6] == 1) {
        /* the chunk contains audio */
        *data_size = vmdaudio_loadsound(s, output_samples, p, 0);
    } else if (buf[6] == 2) {
        /* the chunk contains audio and silence mixed together */
        sound_flags = LE_32(p);
        p += 4;

        /* do something with extrabufs here? */

        while (p < p_end) {
            if (sound_flags & 0x01)
                /* silence */
                *data_size += vmdaudio_loadsound(s, output_samples, p, 1);
            else {
                /* audio */
                *data_size += vmdaudio_loadsound(s, output_samples, p, 0);
                p += s->block_align;
            }
            output_samples += (s->block_align * s->bits / 8);
            sound_flags >>= 1;
        }
    } else if (buf[6] == 3) {
        /* silent chunk */
        *data_size = vmdaudio_loadsound(s, output_samples, p, 1);
    }

    return buf_size;
}


/*
 * Public Data Structures
 */

AVCodec vmdvideo_decoder = {
    "vmdvideo",
    CODEC_TYPE_VIDEO,
    CODEC_ID_VMDVIDEO,
    sizeof(VmdVideoContext),
    vmdvideo_decode_init,
    NULL,
    vmdvideo_decode_end,
    vmdvideo_decode_frame,
    CODEC_CAP_DR1,
};

AVCodec vmdaudio_decoder = {
    "vmdaudio",
    CODEC_TYPE_AUDIO,
    CODEC_ID_VMDAUDIO,
    sizeof(VmdAudioContext),
    vmdaudio_decode_init,
    NULL,
    NULL,
    vmdaudio_decode_frame,
};