static inline void dv_decode_video_segment(DVVideoDecodeContext *s, UINT8 *buf_ptr1, const UINT16 *mb_pos_ptr) { int quant, dc, dct_mode, class1, j; int mb_index, mb_x, mb_y, v, last_index; DCTELEM *block, *block1; int c_offset, bits_left; UINT8 *y_ptr; BlockInfo mb_data[5 * 6], *mb, *mb1; void (*idct_put)(UINT8 *dest, int line_size, DCTELEM *block); UINT8 *buf_ptr; PutBitContext pb, vs_pb; UINT8 mb_bit_buffer[80 + 4]; /* allow some slack */ int mb_bit_count; UINT8 vs_bit_buffer[5 * 80 + 4]; /* allow some slack */ int vs_bit_count; memset(s->block, 0, sizeof(s->block)); /* pass 1 : read DC and AC coefficients in blocks */ buf_ptr = buf_ptr1; block1 = &s->block[0][0]; mb1 = mb_data; init_put_bits(&vs_pb, vs_bit_buffer, 5 * 80, NULL, NULL); vs_bit_count = 0; for(mb_index = 0; mb_index < 5; mb_index++) { /* skip header */ quant = buf_ptr[3] & 0x0f; buf_ptr += 4; init_put_bits(&pb, mb_bit_buffer, 80, NULL, NULL); mb_bit_count = 0; mb = mb1; block = block1; for(j = 0;j < 6; j++) { /* NOTE: size is not important here */ init_get_bits(&s->gb, buf_ptr, 14); /* get the dc */ dc = get_bits(&s->gb, 9); dc = (dc << (32 - 9)) >> (32 - 9); dct_mode = get_bits1(&s->gb); mb->dct_mode = dct_mode; mb->scan_table = s->dv_zigzag[dct_mode]; class1 = get_bits(&s->gb, 2); mb->shift_offset = (class1 == 3); mb->shift_table = s->dv_shift[dct_mode] [quant + dv_quant_offset[class1]]; dc = dc << 2; /* convert to unsigned because 128 is not added in the standard IDCT */ dc += 1024; block[0] = dc; last_index = block_sizes[j]; buf_ptr += last_index >> 3; mb->pos = 0; mb->partial_bit_count = 0; dv_decode_ac(s, mb, block, last_index); /* write the remaining bits in a new buffer only if the block is finished */ bits_left = last_index - s->gb.index; if (mb->eob_reached) { mb->partial_bit_count = 0; mb_bit_count += bits_left; bit_copy(&pb, &s->gb, bits_left); } else { /* should be < 16 bits otherwise a codeword could have been parsed */ mb->partial_bit_count = bits_left; mb->partial_bit_buffer = get_bits(&s->gb, bits_left); } block += 64; mb++; } flush_put_bits(&pb); /* pass 2 : we can do it just after */ #ifdef VLC_DEBUG printf("***pass 2 size=%d\n", mb_bit_count); #endif block = block1; mb = mb1; init_get_bits(&s->gb, mb_bit_buffer, 80); for(j = 0;j < 6; j++) { if (!mb->eob_reached && s->gb.index < mb_bit_count) { dv_decode_ac(s, mb, block, mb_bit_count); /* if still not finished, no need to parse other blocks */ if (!mb->eob_reached) { /* we could not parse the current AC coefficient, so we add the remaining bytes */ bits_left = mb_bit_count - s->gb.index; if (bits_left > 0) { mb->partial_bit_count += bits_left; mb->partial_bit_buffer = (mb->partial_bit_buffer << bits_left) | get_bits(&s->gb, bits_left); } goto next_mb; } } block += 64; mb++; } /* all blocks are finished, so the extra bytes can be used at the video segment level */ bits_left = mb_bit_count - s->gb.index; vs_bit_count += bits_left; bit_copy(&vs_pb, &s->gb, bits_left); next_mb: mb1 += 6; block1 += 6 * 64; } /* we need a pass other the whole video segment */ flush_put_bits(&vs_pb); #ifdef VLC_DEBUG printf("***pass 3 size=%d\n", vs_bit_count); #endif block = &s->block[0][0]; mb = mb_data; init_get_bits(&s->gb, vs_bit_buffer, 5 * 80); for(mb_index = 0; mb_index < 5; mb_index++) { for(j = 0;j < 6; j++) { if (!mb->eob_reached) { #ifdef VLC_DEBUG printf("start %d:%d\n", mb_index, j); #endif dv_decode_ac(s, mb, block, vs_bit_count); } block += 64; mb++; } } /* compute idct and place blocks */ block = &s->block[0][0]; mb = mb_data; for(mb_index = 0; mb_index < 5; mb_index++) { v = *mb_pos_ptr++; mb_x = v & 0xff; mb_y = v >> 8; y_ptr = s->current_picture[0] + (mb_y * s->linesize[0] * 8) + (mb_x * 8); if (s->sampling_411) c_offset = (mb_y * s->linesize[1] * 8) + ((mb_x >> 2) * 8); else c_offset = ((mb_y >> 1) * s->linesize[1] * 8) + ((mb_x >> 1) * 8); for(j = 0;j < 6; j++) { idct_put = s->idct_put[mb->dct_mode]; if (j < 4) { if (s->sampling_411 && mb_x < (704 / 8)) { /* NOTE: at end of line, the macroblock is handled as 420 */ idct_put(y_ptr + (j * 8), s->linesize[0], block); } else { idct_put(y_ptr + ((j & 1) * 8) + ((j >> 1) * 8 * s->linesize[0]), s->linesize[0], block); } } else { if (s->sampling_411 && mb_x >= (704 / 8)) { uint8_t pixels[64], *c_ptr, *c_ptr1, *ptr; int y, linesize; /* NOTE: at end of line, the macroblock is handled as 420 */ idct_put(pixels, 8, block); linesize = s->linesize[6 - j]; c_ptr = s->current_picture[6 - j] + c_offset; ptr = pixels; for(y = 0;y < 8; y++) { /* convert to 411P */ c_ptr1 = c_ptr + linesize; c_ptr1[0] = c_ptr[0] = (ptr[0] + ptr[1]) >> 1; c_ptr1[1] = c_ptr[1] = (ptr[2] + ptr[3]) >> 1; c_ptr1[2] = c_ptr[2] = (ptr[4] + ptr[5]) >> 1; c_ptr1[3] = c_ptr[3] = (ptr[6] + ptr[7]) >> 1; c_ptr += linesize * 2; ptr += 8; } } else { /* don't ask me why they inverted Cb and Cr ! */ idct_put(s->current_picture[6 - j] + c_offset, s->linesize[6 - j], block); } } block += 64; mb++; } } }