static int vqa_decode_chunk(VqaContext *s) { unsigned int chunk_type; unsigned int chunk_size; int byte_skip; unsigned int index = 0; int i; unsigned char r, g, b; int index_shift; int res; int cbf0_chunk = -1; int cbfz_chunk = -1; int cbp0_chunk = -1; int cbpz_chunk = -1; int cpl0_chunk = -1; int cplz_chunk = -1; int vptz_chunk = -1; int x, y; int lines = 0; int pixel_ptr; int vector_index = 0; int lobyte = 0; int hibyte = 0; int lobytes = 0; int hibytes = s->decode_buffer_size / 2; /* first, traverse through the frame and find the subchunks */ while (bytestream2_get_bytes_left(&s->gb) >= 8) { chunk_type = bytestream2_get_be32u(&s->gb); index = bytestream2_tell(&s->gb); chunk_size = bytestream2_get_be32u(&s->gb); switch (chunk_type) { case CBF0_TAG: cbf0_chunk = index; break; case CBFZ_TAG: cbfz_chunk = index; break; case CBP0_TAG: cbp0_chunk = index; break; case CBPZ_TAG: cbpz_chunk = index; break; case CPL0_TAG: cpl0_chunk = index; break; case CPLZ_TAG: cplz_chunk = index; break; case VPTZ_TAG: vptz_chunk = index; break; default: av_log(s->avctx, AV_LOG_ERROR, " VQA video: Found unknown chunk type: %c%c%c%c (%08X)\n", (chunk_type >> 24) & 0xFF, (chunk_type >> 16) & 0xFF, (chunk_type >> 8) & 0xFF, (chunk_type >> 0) & 0xFF, chunk_type); break; } byte_skip = chunk_size & 0x01; bytestream2_skip(&s->gb, chunk_size + byte_skip); } /* next, deal with the palette */ if ((cpl0_chunk != -1) && (cplz_chunk != -1)) { /* a chunk should not have both chunk types */ av_log(s->avctx, AV_LOG_ERROR, " VQA video: problem: found both CPL0 and CPLZ chunks\n"); return AVERROR_INVALIDDATA; } /* decompress the palette chunk */ if (cplz_chunk != -1) { /* yet to be handled */ } /* convert the RGB palette into the machine's endian format */ if (cpl0_chunk != -1) { bytestream2_seek(&s->gb, cpl0_chunk, SEEK_SET); chunk_size = bytestream2_get_be32(&s->gb); /* sanity check the palette size */ if (chunk_size / 3 > 256 || chunk_size > bytestream2_get_bytes_left(&s->gb)) { av_log(s->avctx, AV_LOG_ERROR, " VQA video: problem: found a palette chunk with %d colors\n", chunk_size / 3); return AVERROR_INVALIDDATA; } for (i = 0; i < chunk_size / 3; i++) { /* scale by 4 to transform 6-bit palette -> 8-bit */ r = bytestream2_get_byteu(&s->gb) * 4; g = bytestream2_get_byteu(&s->gb) * 4; b = bytestream2_get_byteu(&s->gb) * 4; s->palette[i] = (r << 16) | (g << 8) | (b); } } /* next, look for a full codebook */ if ((cbf0_chunk != -1) && (cbfz_chunk != -1)) { /* a chunk should not have both chunk types */ av_log(s->avctx, AV_LOG_ERROR, " VQA video: problem: found both CBF0 and CBFZ chunks\n"); return AVERROR_INVALIDDATA; } /* decompress the full codebook chunk */ if (cbfz_chunk != -1) { bytestream2_seek(&s->gb, cbfz_chunk, SEEK_SET); chunk_size = bytestream2_get_be32(&s->gb); if ((res = decode_format80(&s->gb, chunk_size, s->codebook, s->codebook_size, 0)) < 0) return res; } /* copy a full codebook */ if (cbf0_chunk != -1) { bytestream2_seek(&s->gb, cbf0_chunk, SEEK_SET); chunk_size = bytestream2_get_be32(&s->gb); /* sanity check the full codebook size */ if (chunk_size > MAX_CODEBOOK_SIZE) { av_log(s->avctx, AV_LOG_ERROR, " VQA video: problem: CBF0 chunk too large (0x%X bytes)\n", chunk_size); return AVERROR_INVALIDDATA; } bytestream2_get_buffer(&s->gb, s->codebook, chunk_size); } /* decode the frame */ if (vptz_chunk == -1) { /* something is wrong if there is no VPTZ chunk */ av_log(s->avctx, AV_LOG_ERROR, " VQA video: problem: no VPTZ chunk found\n"); return AVERROR_INVALIDDATA; } bytestream2_seek(&s->gb, vptz_chunk, SEEK_SET); chunk_size = bytestream2_get_be32(&s->gb); if ((res = decode_format80(&s->gb, chunk_size, s->decode_buffer, s->decode_buffer_size, 1)) < 0) return res; /* render the final PAL8 frame */ if (s->vector_height == 4) index_shift = 4; else index_shift = 3; for (y = 0; y < s->frame.linesize[0] * s->height; y += s->frame.linesize[0] * s->vector_height) { for (x = y; x < y + s->width; x += 4, lobytes++, hibytes++) { pixel_ptr = x; /* get the vector index, the method for which varies according to * VQA file version */ switch (s->vqa_version) { case 1: lobyte = s->decode_buffer[lobytes * 2]; hibyte = s->decode_buffer[(lobytes * 2) + 1]; vector_index = ((hibyte << 8) | lobyte) >> 3; vector_index <<= index_shift; lines = s->vector_height; /* uniform color fill - a quick hack */ if (hibyte == 0xFF) { while (lines--) { s->frame.data[0][pixel_ptr + 0] = 255 - lobyte; s->frame.data[0][pixel_ptr + 1] = 255 - lobyte; s->frame.data[0][pixel_ptr + 2] = 255 - lobyte; s->frame.data[0][pixel_ptr + 3] = 255 - lobyte; pixel_ptr += s->frame.linesize[0]; } lines=0; } break; case 2: lobyte = s->decode_buffer[lobytes]; hibyte = s->decode_buffer[hibytes]; vector_index = (hibyte << 8) | lobyte; vector_index <<= index_shift; lines = s->vector_height; break; case 3: /* not implemented yet */ lines = 0; break; } while (lines--) { s->frame.data[0][pixel_ptr + 0] = s->codebook[vector_index++]; s->frame.data[0][pixel_ptr + 1] = s->codebook[vector_index++]; s->frame.data[0][pixel_ptr + 2] = s->codebook[vector_index++]; s->frame.data[0][pixel_ptr + 3] = s->codebook[vector_index++]; pixel_ptr += s->frame.linesize[0]; } } } /* handle partial codebook */ if ((cbp0_chunk != -1) && (cbpz_chunk != -1)) { /* a chunk should not have both chunk types */ av_log(s->avctx, AV_LOG_ERROR, " VQA video: problem: found both CBP0 and CBPZ chunks\n"); return AVERROR_INVALIDDATA; } if (cbp0_chunk != -1) { bytestream2_seek(&s->gb, cbp0_chunk, SEEK_SET); chunk_size = bytestream2_get_be32(&s->gb); /* accumulate partial codebook */ bytestream2_get_buffer(&s->gb, &s->next_codebook_buffer[s->next_codebook_buffer_index], chunk_size); s->next_codebook_buffer_index += chunk_size; s->partial_countdown--; if (s->partial_countdown == 0) { /* time to replace codebook */ memcpy(s->codebook, s->next_codebook_buffer, s->next_codebook_buffer_index); /* reset accounting */ s->next_codebook_buffer_index = 0; s->partial_countdown = s->partial_count; } } if (cbpz_chunk != -1) { bytestream2_seek(&s->gb, cbpz_chunk, SEEK_SET); chunk_size = bytestream2_get_be32(&s->gb); /* accumulate partial codebook */ bytestream2_get_buffer(&s->gb, &s->next_codebook_buffer[s->next_codebook_buffer_index], chunk_size); s->next_codebook_buffer_index += chunk_size; s->partial_countdown--; if (s->partial_countdown == 0) { GetByteContext gb; bytestream2_init(&gb, s->next_codebook_buffer, s->next_codebook_buffer_index); /* decompress codebook */ if ((res = decode_format80(&gb, s->next_codebook_buffer_index, s->codebook, s->codebook_size, 0)) < 0) return res; /* reset accounting */ s->next_codebook_buffer_index = 0; s->partial_countdown = s->partial_count; } } return 0; }