static int bitplane_decoding(uint8_t* data, int *raw_flag, VC1Context *v) { GetBitContext *gb = &v->s.gb; int imode, x, y, code, offset; uint8_t invert, *planep = data; int width, height, stride; width = v->s.mb_width; height = v->s.mb_height >> v->field_mode; stride = v->s.mb_stride; invert = get_bits1(gb); imode = get_vlc2(gb, ff_vc1_imode_vlc.table, VC1_IMODE_VLC_BITS, 1); *raw_flag = 0; switch (imode) { case IMODE_RAW: //Data is actually read in the MB layer (same for all tests == "raw") *raw_flag = 1; //invert ignored return invert; case IMODE_DIFF2: case IMODE_NORM2: if ((height * width) & 1) { *planep++ = get_bits1(gb); offset = 1; } else offset = 0; // decode bitplane as one long line for (y = offset; y < height * width; y += 2) { code = get_vlc2(gb, ff_vc1_norm2_vlc.table, VC1_NORM2_VLC_BITS, 1); *planep++ = code & 1; offset++; if (offset == width) { offset = 0; planep += stride - width; } *planep++ = code >> 1; offset++; if (offset == width) { offset = 0; planep += stride - width; } } break; case IMODE_DIFF6: case IMODE_NORM6: if (!(height % 3) && (width % 3)) { // use 2x3 decoding for (y = 0; y < height; y += 3) { for (x = width & 1; x < width; x += 2) { code = get_vlc2(gb, ff_vc1_norm6_vlc.table, VC1_NORM6_VLC_BITS, 2); if (code < 0) { av_log(v->s.avctx, AV_LOG_DEBUG, "invalid NORM-6 VLC\n"); return -1; } planep[x + 0] = (code >> 0) & 1; planep[x + 1] = (code >> 1) & 1; planep[x + 0 + stride] = (code >> 2) & 1; planep[x + 1 + stride] = (code >> 3) & 1; planep[x + 0 + stride * 2] = (code >> 4) & 1; planep[x + 1 + stride * 2] = (code >> 5) & 1; } planep += stride * 3; } if (width & 1) decode_colskip(data, 1, height, stride, &v->s.gb); } else { // 3x2 planep += (height & 1) * stride; for (y = height & 1; y < height; y += 2) { for (x = width % 3; x < width; x += 3) { code = get_vlc2(gb, ff_vc1_norm6_vlc.table, VC1_NORM6_VLC_BITS, 2); if (code < 0) { av_log(v->s.avctx, AV_LOG_DEBUG, "invalid NORM-6 VLC\n"); return -1; } planep[x + 0] = (code >> 0) & 1; planep[x + 1] = (code >> 1) & 1; planep[x + 2] = (code >> 2) & 1; planep[x + 0 + stride] = (code >> 3) & 1; planep[x + 1 + stride] = (code >> 4) & 1; planep[x + 2 + stride] = (code >> 5) & 1; } planep += stride * 2; } x = width % 3; if (x) decode_colskip(data, x, height, stride, &v->s.gb); if (height & 1) decode_rowskip(data + x, width - x, 1, stride, &v->s.gb); } break; case IMODE_ROWSKIP: decode_rowskip(data, width, height, stride, &v->s.gb); break; case IMODE_COLSKIP: decode_colskip(data, width, height, stride, &v->s.gb); break; default: break; } /* Applying diff operator */ if (imode == IMODE_DIFF2 || imode == IMODE_DIFF6) { planep = data; planep[0] ^= invert; for (x = 1; x < width; x++) planep[x] ^= planep[x-1]; for (y = 1; y < height; y++) { planep += stride; planep[0] ^= planep[-stride]; for (x = 1; x < width; x++) { if (planep[x-1] != planep[x-stride]) planep[x] ^= invert; else planep[x] ^= planep[x-1]; } } } else if (invert) { planep = data; for (x = 0; x < stride * height; x++) planep[x] = !planep[x]; //FIXME stride } return (imode << 1) + invert; }