static int vqa_decode_init(AVCodecContext *avctx) { VqaContext *s = (VqaContext *)avctx->priv_data; unsigned char *vqa_header; int i, j, codebook_index;; s->avctx = avctx; avctx->pix_fmt = PIX_FMT_PAL8; avctx->has_b_frames = 0; dsputil_init(&s->dsp, avctx); /* make sure the extradata made it */ if (s->avctx->extradata_size != VQA_HEADER_SIZE) { av_log(s->avctx, AV_LOG_ERROR, " VQA video: expected extradata size of %d\n", VQA_HEADER_SIZE); /* load up the VQA parameters from the header */ vqa_header = (unsigned char *)s->avctx->extradata; s->vqa_version = vqa_header[0]; s->width = LE_16(&vqa_header[6]); s->height = LE_16(&vqa_header[8]); s->vector_width = vqa_header[10]; s->vector_height = vqa_header[11]; s->partial_count = s->partial_countdown = vqa_header[13]; /* the vector dimensions have to meet very stringent requirements */ if ((s->vector_width != 4) || ((s->vector_height != 2) && (s->vector_height != 4))) { /* return without further initialization */ /* allocate codebooks */ s->codebook_size = MAX_CODEBOOK_SIZE; s->codebook = av_malloc(s->codebook_size); s->next_codebook_buffer = av_malloc(s->codebook_size); /* initialize the solid-color vectors */ if (s->vector_height == 4) { codebook_index = 0xFF00 * 16; for (i = 0; i < 256; i++) for (j = 0; j < 16; j++) s->codebook[codebook_index++] = i; } else { codebook_index = 0xF00 * 8; for (i = 0; i < 256; i++) for (j = 0; j < 8; j++) s->codebook[codebook_index++] = i; s->next_codebook_buffer_index = 0; /* allocate decode buffer */ s->decode_buffer_size = (s->width / s->vector_width) * (s->height / s->vector_height) * 2; s->decode_buffer = av_malloc(s->decode_buffer_size); s->frame.data[0] = NULL; return 0;