lcl.c.svn-base

ffmpeg是一个大项目

{
    LclContext * const c = (LclContext *)avctx->priv_data;
    unsigned int basesize = avctx->width * avctx->height;
    unsigned int max_basesize = ((avctx->width + 3) & ~3) * ((avctx->height + 3) & ~3);
    unsigned int max_decomp_size;
    int zret; // Zlib return code

    c->avctx = avctx;
    avctx->has_b_frames = 0;

    c->pic.data[0] = NULL;

#ifdef CONFIG_ZLIB
    // Needed if zlib unused or init aborted before inflateInit
    memset(&(c->zstream), 0, sizeof(z_stream));
#endif

    if (avctx->extradata_size < 8) {
        av_log(avctx, AV_LOG_ERROR, "Extradata size too small.\n");
        return 1;
    }

    if (avcodec_check_dimensions(avctx, avctx->width, avctx->height) < 0) {
        return 1;
    }

    /* Check codec type */
    if (((avctx->codec_id == CODEC_ID_MSZH)  && (*((char *)avctx->extradata + 7) != CODEC_MSZH)) ||
        ((avctx->codec_id == CODEC_ID_ZLIB)  && (*((char *)avctx->extradata + 7) != CODEC_ZLIB))) {
        av_log(avctx, AV_LOG_ERROR, "Codec id and codec type mismatch. This should not happen.\n");
    }

    /* Detect image type */
    switch (c->imgtype = *((char *)avctx->extradata + 4)) {
        case IMGTYPE_YUV111:
            c->decomp_size = basesize * 3;
            max_decomp_size = max_basesize * 3;
            av_log(avctx, AV_LOG_INFO, "Image type is YUV 1:1:1.\n");
            break;
        case IMGTYPE_YUV422:
            c->decomp_size = basesize * 2;
            max_decomp_size = max_basesize * 2;
            av_log(avctx, AV_LOG_INFO, "Image type is YUV 4:2:2.\n");
            break;
        case IMGTYPE_RGB24:
            c->decomp_size = basesize * 3;
            max_decomp_size = max_basesize * 3;
            av_log(avctx, AV_LOG_INFO, "Image type is RGB 24.\n");
            break;
        case IMGTYPE_YUV411:
            c->decomp_size = basesize / 2 * 3;
            max_decomp_size = max_basesize / 2 * 3;
            av_log(avctx, AV_LOG_INFO, "Image type is YUV 4:1:1.\n");
            break;
        case IMGTYPE_YUV211:
            c->decomp_size = basesize * 2;
            max_decomp_size = max_basesize * 2;
            av_log(avctx, AV_LOG_INFO, "Image type is YUV 2:1:1.\n");
            break;
        case IMGTYPE_YUV420:
            c->decomp_size = basesize / 2 * 3;
            max_decomp_size = max_basesize / 2 * 3;
            av_log(avctx, AV_LOG_INFO, "Image type is YUV 4:2:0.\n");
            break;
        default:
            av_log(avctx, AV_LOG_ERROR, "Unsupported image format %d.\n", c->imgtype);
            return 1;
    }

    /* Detect compression method */
    c->compression = *((char *)avctx->extradata + 5);
    switch (avctx->codec_id) {
        case CODEC_ID_MSZH:
            switch (c->compression) {
                case COMP_MSZH:
                    av_log(avctx, AV_LOG_INFO, "Compression enabled.\n");
                    break;
                case COMP_MSZH_NOCOMP:
                    c->decomp_size = 0;
                    av_log(avctx, AV_LOG_INFO, "No compression.\n");
                    break;
                default:
                    av_log(avctx, AV_LOG_ERROR, "Unsupported compression format for MSZH (%d).\n", c->compression);
                    return 1;
            }
            break;
        case CODEC_ID_ZLIB:
#ifdef CONFIG_ZLIB
            switch (c->compression) {
                case COMP_ZLIB_HISPEED:
                    av_log(avctx, AV_LOG_INFO, "High speed compression.\n");
                    break;
                case COMP_ZLIB_HICOMP:
                    av_log(avctx, AV_LOG_INFO, "High compression.\n");
                    break;
                case COMP_ZLIB_NORMAL:
                    av_log(avctx, AV_LOG_INFO, "Normal compression.\n");
                    break;
                default:
                    if ((c->compression < Z_NO_COMPRESSION) || (c->compression > Z_BEST_COMPRESSION)) {
                            av_log(avctx, AV_LOG_ERROR, "Unsupported compression level for ZLIB: (%d).\n", c->compression);
                        return 1;
                    }
                    av_log(avctx, AV_LOG_INFO, "Compression level for ZLIB: (%d).\n", c->compression);
            }
#else
            av_log(avctx, AV_LOG_ERROR, "Zlib support not compiled.\n");
            return 1;
#endif
            break;
        default:
            av_log(avctx, AV_LOG_ERROR, "BUG! Unknown codec in compression switch.\n");
            return 1;
    }

    /* Allocate decompression buffer */
    if (c->decomp_size) {
        if ((c->decomp_buf = av_malloc(max_decomp_size)) == NULL) {
            av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
            return 1;
        }
    }

    /* Detect flags */
    c->flags = *((char *)avctx->extradata + 6);
    if (c->flags & FLAG_MULTITHREAD)
        av_log(avctx, AV_LOG_INFO, "Multithread encoder flag set.\n");
    if (c->flags & FLAG_NULLFRAME)
        av_log(avctx, AV_LOG_INFO, "Nullframe insertion flag set.\n");
    if ((avctx->codec_id == CODEC_ID_ZLIB) && (c->flags & FLAG_PNGFILTER))
        av_log(avctx, AV_LOG_INFO, "PNG filter flag set.\n");
    if (c->flags & FLAGMASK_UNUSED)
        av_log(avctx, AV_LOG_ERROR, "Unknown flag set (%d).\n", c->flags);

    /* If needed init zlib */
    if (avctx->codec_id == CODEC_ID_ZLIB) {
#ifdef CONFIG_ZLIB
        c->zstream.zalloc = Z_NULL;
        c->zstream.zfree = Z_NULL;
        c->zstream.opaque = Z_NULL;
        zret = inflateInit(&(c->zstream));
        if (zret != Z_OK) {
            av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
            return 1;
        }
#else
    av_log(avctx, AV_LOG_ERROR, "Zlib support not compiled.\n");
    return 1;
#endif
    }

    avctx->pix_fmt = PIX_FMT_BGR24;

    return 0;
}



/*
 *
 * Init lcl encoder
 *
 */
static int encode_init(AVCodecContext *avctx)
{
    LclContext *c = avctx->priv_data;
    int zret; // Zlib return code

#ifndef CONFIG_ZLIB
    av_log(avctx, AV_LOG_ERROR, "Zlib support not compiled.\n");
    return 1;
#else

    c->avctx= avctx;

    assert(avctx->width && avctx->height);

    avctx->extradata= av_mallocz(8);
    avctx->coded_frame= &c->pic;

    // Will be user settable someday
    c->compression = 6;
    c->flags = 0;

    switch(avctx->pix_fmt){
        case PIX_FMT_BGR24:
            c->imgtype = IMGTYPE_RGB24;
            c->decomp_size = avctx->width * avctx->height * 3;
            avctx->bits_per_sample= 24;
            break;
        default:
            av_log(avctx, AV_LOG_ERROR, "Format %d not supported\n", avctx->pix_fmt);
            return -1;
    }

    ((uint8_t*)avctx->extradata)[0]= 4;
    ((uint8_t*)avctx->extradata)[1]= 0;
    ((uint8_t*)avctx->extradata)[2]= 0;
    ((uint8_t*)avctx->extradata)[3]= 0;
    ((uint8_t*)avctx->extradata)[4]= c->imgtype;
    ((uint8_t*)avctx->extradata)[5]= c->compression;
    ((uint8_t*)avctx->extradata)[6]= c->flags;
    ((uint8_t*)avctx->extradata)[7]= CODEC_ZLIB;
    c->avctx->extradata_size= 8;

    c->zstream.zalloc = Z_NULL;
    c->zstream.zfree = Z_NULL;
    c->zstream.opaque = Z_NULL;
    zret = deflateInit(&(c->zstream), c->compression);
    if (zret != Z_OK) {
        av_log(avctx, AV_LOG_ERROR, "Deflate init error: %d\n", zret);
        return 1;
    }

        /* Conservative upper bound taken from zlib v1.2.1 source */
        c->max_comp_size = c->decomp_size + ((c->decomp_size + 7) >> 3) +
                           ((c->decomp_size + 63) >> 6) + 11;
    if ((c->comp_buf = av_malloc(c->max_comp_size)) == NULL) {
        av_log(avctx, AV_LOG_ERROR, "Can't allocate compression buffer.\n");
        return 1;
    }

    return 0;
#endif
}





/*
 *
 * Uninit lcl decoder
 *
 */
static int decode_end(AVCodecContext *avctx)
{
        LclContext * const c = (LclContext *)avctx->priv_data;

        if (c->pic.data[0])
                avctx->release_buffer(avctx, &c->pic);
#ifdef CONFIG_ZLIB
    inflateEnd(&(c->zstream));
#endif

        return 0;
}



/*
 *
 * Uninit lcl encoder
 *
 */
static int encode_end(AVCodecContext *avctx)
{
    LclContext *c = avctx->priv_data;

    av_freep(&avctx->extradata);
    av_freep(&c->comp_buf);
#ifdef CONFIG_ZLIB
    deflateEnd(&(c->zstream));
#endif

    return 0;
}

AVCodec mszh_decoder = {
        "mszh",
        CODEC_TYPE_VIDEO,
        CODEC_ID_MSZH,
        sizeof(LclContext),
        decode_init,
        NULL,
        decode_end,
        decode_frame,
        CODEC_CAP_DR1,
};


AVCodec zlib_decoder = {
        "zlib",
        CODEC_TYPE_VIDEO,
        CODEC_ID_ZLIB,
        sizeof(LclContext),
        decode_init,
        NULL,
        decode_end,
        decode_frame,
        CODEC_CAP_DR1,
};

#ifdef CONFIG_ENCODERS

AVCodec zlib_encoder = {
    "zlib",
    CODEC_TYPE_VIDEO,
    CODEC_ID_ZLIB,
    sizeof(LclContext),
    encode_init,
    encode_frame,
    encode_end,
};

#endif //CONFIG_ENCODERS