You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
312 lines
8.8 KiB
312 lines
8.8 KiB
/* Copyright (C) 2005 Ole André Vadla Ravnås <oleavr@gmail.com>
|
|
*
|
|
* This library is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2.1 of the License, or (at your option) any later version.
|
|
*
|
|
* This library is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public
|
|
* License along with this library; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
#include <string.h>
|
|
#include "mimic-private.h"
|
|
|
|
|
|
static gboolean decode(MimCtx *ctx, gboolean is_pframe);
|
|
|
|
/**
|
|
* Decode a MIMIC-encoded frame into RGB data.
|
|
*
|
|
* @param ctx the mimic context
|
|
* @param input_buffer buffer containing the MIMIC-encoded frame to decode
|
|
* @param output_buffer buffer that will receive the decoded frame in RGB 24-bpp packed pixel top-down format
|
|
* (use #mimic_get_property to determine the required buffer size, as well as frame width and height)
|
|
* @returns #TRUE on success
|
|
*/
|
|
gboolean mimic_decode_frame(MimCtx *ctx,
|
|
const guchar *input_buffer,
|
|
guchar *output_buffer)
|
|
{
|
|
gboolean result, is_pframe;
|
|
guchar *input_y, *input_cr, *input_cb;
|
|
gint width, height;
|
|
|
|
/*
|
|
* Some sanity checks.
|
|
*/
|
|
if (ctx == NULL || input_buffer == NULL || output_buffer == NULL)
|
|
{
|
|
return FALSE;
|
|
}
|
|
|
|
if (!ctx->decoder_initialized)
|
|
{
|
|
return FALSE;
|
|
}
|
|
|
|
/*
|
|
* Get frame dimensions.
|
|
*/
|
|
width = GUINT16_FROM_LE(*((guint16 *) (input_buffer + 4)));
|
|
height = GUINT16_FROM_LE(*((guint16 *) (input_buffer + 6)));
|
|
|
|
/*
|
|
* Resolution changing is not supported.
|
|
*/
|
|
if (width != ctx->frame_width ||
|
|
height != ctx->frame_height)
|
|
{
|
|
return FALSE;
|
|
}
|
|
|
|
/*
|
|
* Increment frame counter.
|
|
*/
|
|
ctx->frame_num++;
|
|
|
|
/*
|
|
* Initialize state.
|
|
*/
|
|
ctx->quality = GUINT16_FROM_LE(*((guint16 *) (input_buffer + 2)));
|
|
is_pframe = GUINT32_FROM_LE(*((guint32 *) (input_buffer + 12)));
|
|
ctx->num_coeffs = input_buffer[16];
|
|
|
|
ctx->data_buffer = (gchar *) (input_buffer + 20);
|
|
ctx->data_index = 0;
|
|
ctx->cur_chunk_len = 16;
|
|
ctx->read_odd = FALSE;
|
|
|
|
/*
|
|
* Decode frame.
|
|
*/
|
|
if (!(is_pframe && ctx->prev_frame_buf == NULL))
|
|
result = decode(ctx, is_pframe);
|
|
else
|
|
{
|
|
result = FALSE;
|
|
}
|
|
|
|
/*
|
|
* Perform YUV 420 to RGB conversion.
|
|
*/
|
|
input_y = ctx->cur_frame_buf;
|
|
input_cr = ctx->cur_frame_buf + ctx->y_size;
|
|
input_cb = ctx->cur_frame_buf + ctx->y_size + ctx->crcb_size;
|
|
|
|
_yuv_to_rgb(input_y,
|
|
input_cb,
|
|
input_cr,
|
|
output_buffer,
|
|
ctx->frame_width,
|
|
ctx->frame_height);
|
|
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* decode_main
|
|
*
|
|
* Main decoding loop.
|
|
*/
|
|
static gboolean decode(MimCtx *ctx, gboolean is_pframe)
|
|
{
|
|
gint y, x, i, j, chrom_ch, *bptr, base_offset, offset;
|
|
gint dct_block[64];
|
|
guchar *src, *dst, *p;
|
|
guint32 bit;
|
|
|
|
/*
|
|
* Clear Cr and Cb planes.
|
|
*/
|
|
p = ctx->cur_frame_buf + ctx->y_size;
|
|
memset(p, 128, 2 * ctx->crcb_size);
|
|
|
|
/*
|
|
* Decode Y plane.
|
|
*/
|
|
for (y = 0; y < ctx->num_vblocks_y; y++) {
|
|
|
|
base_offset = ctx->y_stride * 8 * y;
|
|
|
|
src = ctx->prev_frame_buf + base_offset;
|
|
dst = ctx->cur_frame_buf + base_offset;
|
|
|
|
for (x = 0; x < ctx->num_hblocks_y; x++) {
|
|
|
|
/* Check for a change condition in the current block. */
|
|
|
|
if (is_pframe)
|
|
bit = _read_bits(ctx, 1);
|
|
else
|
|
bit = 0;
|
|
|
|
if (bit == 0) {
|
|
|
|
/* Yes: Is the new content the same as it was in one of
|
|
* the 15 last frames preceding the previous? */
|
|
|
|
if (is_pframe)
|
|
bit = _read_bits(ctx, 1);
|
|
|
|
if (bit == 0) {
|
|
|
|
/* No: decode it. */
|
|
|
|
if (_vlc_decode_block(ctx, dct_block, ctx->num_coeffs) == FALSE) {
|
|
|
|
return FALSE;
|
|
}
|
|
|
|
_idct_dequant_block(ctx, dct_block, 0);
|
|
|
|
bptr = dct_block;
|
|
for (i = 0; i < 8; i++) {
|
|
offset = ctx->y_stride * i;
|
|
|
|
for (j = 0; j < 8; j++) {
|
|
guint v;
|
|
|
|
if (bptr[j] <= 255)
|
|
v = (bptr[j] >= 0) ? bptr[j] : 0;
|
|
else
|
|
v = 255;
|
|
|
|
*(dst + offset + j) = v;
|
|
}
|
|
|
|
bptr += 8;
|
|
}
|
|
} else {
|
|
guint32 backref;
|
|
|
|
/* Yes: read the backreference (4 bits) and copy. */
|
|
|
|
backref = _read_bits(ctx, 4);
|
|
|
|
p = ctx->buf_ptrs[(ctx->ptr_index + backref) % 16];
|
|
p += base_offset + (x * 8);
|
|
|
|
for (i = 0; i < 8; i++) {
|
|
offset = ctx->y_stride * i;
|
|
|
|
memcpy(dst + offset, p + offset, 8);
|
|
}
|
|
}
|
|
} else {
|
|
|
|
/* No change no worries: just copy from the previous frame. */
|
|
|
|
for (i = 0; i < 8; i++) {
|
|
offset = ctx->y_stride * i;
|
|
|
|
memcpy(dst + offset, src + offset, 8);
|
|
}
|
|
}
|
|
|
|
src += 8;
|
|
dst += 8;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Decode Cr and Cb planes.
|
|
*/
|
|
for (chrom_ch = 0; chrom_ch < 2; chrom_ch++) {
|
|
|
|
base_offset = ctx->y_size + (ctx->crcb_size * chrom_ch);
|
|
|
|
for (y = 0; y < ctx->num_vblocks_cbcr; y++) {
|
|
guint num_rows = 8;
|
|
|
|
/* The last row of blocks in chrominance for 160x120 resolution
|
|
* is half the normal height and must be accounted for. */
|
|
if (y + 1 == ctx->num_vblocks_cbcr && ctx->frame_height % 16 != 0)
|
|
num_rows = 4;
|
|
|
|
offset = base_offset + (ctx->crcb_stride * 8 * y);
|
|
|
|
src = ctx->prev_frame_buf + offset;
|
|
dst = ctx->cur_frame_buf + offset;
|
|
|
|
for (x = 0; x < ctx->num_hblocks_cbcr; x++) {
|
|
|
|
/* Check for a change condition in the current block. */
|
|
|
|
if (is_pframe)
|
|
bit = _read_bits(ctx, 1);
|
|
else
|
|
bit = 1;
|
|
|
|
if (bit == 1) {
|
|
|
|
/* Yes: decode it. */
|
|
|
|
if (_vlc_decode_block(ctx, dct_block, ctx->num_coeffs) == FALSE) {
|
|
|
|
/* Corrupted frame: clear Cr and Cb planes and return. */
|
|
p = ctx->cur_frame_buf + ctx->y_size;
|
|
memset(p, 128, ctx->crcb_size * 2);
|
|
|
|
return FALSE;
|
|
}
|
|
|
|
_idct_dequant_block(ctx, dct_block, 1);
|
|
|
|
for (i = 0; i < num_rows; i++) {
|
|
p = dst + (ctx->crcb_stride * i);
|
|
|
|
for (j = 0; j < 8; j++)
|
|
p[j] = dct_block[(i * 8) + j];
|
|
}
|
|
|
|
} else {
|
|
|
|
/* No change no worries: just copy from the previous frame. */
|
|
|
|
for (i = 0; i < num_rows; i++) {
|
|
offset = ctx->crcb_stride * i;
|
|
|
|
memcpy(dst + offset, src + offset, 8);
|
|
}
|
|
}
|
|
|
|
src += 8;
|
|
dst += 8;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Make a copy of the current frame and store in
|
|
* the circular pointer list of 16 entries.
|
|
*/
|
|
ctx->prev_frame_buf = ctx->buf_ptrs[ctx->ptr_index];
|
|
memcpy(ctx->prev_frame_buf, ctx->cur_frame_buf,
|
|
ctx->y_size + (ctx->crcb_size * 2));
|
|
|
|
if (--ctx->ptr_index < 0)
|
|
ctx->ptr_index = 15;
|
|
|
|
/*
|
|
* Perform deblocking on all planes.
|
|
*/
|
|
_deblock(ctx->cur_frame_buf,
|
|
ctx->y_stride, ctx->y_row_count);
|
|
|
|
_deblock(ctx->cur_frame_buf + ctx->y_size,
|
|
ctx->crcb_stride, ctx->crcb_row_count);
|
|
|
|
_deblock(ctx->cur_frame_buf + ctx->y_size + ctx->crcb_size,
|
|
ctx->crcb_stride, ctx->crcb_row_count);
|
|
|
|
return TRUE;
|
|
}
|
|
|