Function dds_decode

libavcodec/dds.c:567–706

}

static int dds_decode(AVCodecContext *avctx, AVFrame *frame,
                      int *got_frame, AVPacket *avpkt)
{
    DDSContext *ctx = avctx->priv_data;
    GetByteContext *gbc = &ctx->gbc;
    int mipmap;
    int ret;
    int width, height;

    ff_texturedsp_init(&ctx->texdsp);
    bytestream2_init(gbc, avpkt->data, avpkt->size);

    if (bytestream2_get_bytes_left(gbc) < 128) {
        av_log(avctx, AV_LOG_ERROR, "Frame is too small (%d).\n",
               bytestream2_get_bytes_left(gbc));
        return AVERROR_INVALIDDATA;
    }

    if (bytestream2_get_le32(gbc) != MKTAG('D', 'D', 'S', ' ') ||
        bytestream2_get_le32(gbc) != 124) { // header size
        av_log(avctx, AV_LOG_ERROR, "Invalid DDS header.\n");
        return AVERROR_INVALIDDATA;
    }

    bytestream2_skip(gbc, 4); // flags

    height = bytestream2_get_le32(gbc);
    width  = bytestream2_get_le32(gbc);
    ret = ff_set_dimensions(avctx, width, height);
    if (ret < 0) {
        av_log(avctx, AV_LOG_ERROR, "Invalid image size %dx%d.\n",
               avctx->width, avctx->height);
        return ret;
    }

    /* Since codec is based on 4x4 blocks, size is aligned to 4. */
    avctx->coded_width  = FFALIGN(avctx->width,  TEXTURE_BLOCK_W);
    avctx->coded_height = FFALIGN(avctx->height, TEXTURE_BLOCK_H);

    bytestream2_skip(gbc, 4); // pitch
    bytestream2_skip(gbc, 4); // depth
    mipmap = bytestream2_get_le32(gbc);
    if (mipmap != 0)
        av_log(avctx, AV_LOG_VERBOSE, "Found %d mipmaps (ignored).\n", mipmap);

    /* Extract pixel format information, considering additional elements
     * in reserved1 and reserved2. */
    ret = parse_pixel_format(avctx);
    if (ret < 0)
        return ret;

    ret = ff_get_buffer(avctx, frame, 0);
    if (ret < 0)
        return ret;

    if (ctx->compressed) {
        int size = (avctx->coded_height / TEXTURE_BLOCK_H) *
                   (avctx->coded_width / TEXTURE_BLOCK_W) * ctx->dec.tex_ratio;