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/*
* Creative YUV (CYUV) Video Decoder
* by Mike Melanson (melanson@pcisys.net)
* based on "Creative YUV (CYUV) stream format for AVI":
* http://www.csse.monash.edu.au/~timf/videocodec/cyuv.txt
*
* Copyright (C) 2003 the ffmpeg project
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* Creative YUV (CYUV) Video Decoder.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "avcodec.h"
#include "internal.h"
#include "libavutil/internal.h"
typedef struct CyuvDecodeContext {
AVCodecContext *avctx;
int width, height;
} CyuvDecodeContext;
static av_cold int cyuv_decode_init(AVCodecContext *avctx)
{
CyuvDecodeContext *s = avctx->priv_data;
s->avctx = avctx;
s->width = avctx->width;
/* width needs to be divisible by 4 for this codec to work */
if (s->width & 0x3)
return AVERROR_INVALIDDATA;
s->height = avctx->height;
avctx->pix_fmt = AV_PIX_FMT_YUV411P;
return 0;
}
static int cyuv_decode_frame(AVCodecContext *avctx,
void *data, int *got_frame,
AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
CyuvDecodeContext *s=avctx->priv_data;
AVFrame *frame = data;
unsigned char *y_plane;
unsigned char *u_plane;
unsigned char *v_plane;
int y_ptr;
int u_ptr;
int v_ptr;
/* prediction error tables (make it clear that they are signed values) */
const signed char *y_table = (const signed char*)buf + 0;
const signed char *u_table = (const signed char*)buf + 16;
const signed char *v_table = (const signed char*)buf + 32;
unsigned char y_pred, u_pred, v_pred;
int stream_ptr;
unsigned char cur_byte;
int pixel_groups;
int ret;
if (avctx->codec_id == AV_CODEC_ID_AURA) {
y_table = u_table;
u_table = v_table;
}
/* sanity check the buffer size: A buffer has 3x16-bytes tables
* followed by (height) lines each with 3 bytes to represent groups
* of 4 pixels. Thus, the total size of the buffer ought to be:
* (3 * 16) + height * (width * 3 / 4) */
if (buf_size != 48 + s->height * (s->width * 3 / 4)) {
av_log(avctx, AV_LOG_ERROR, "got a buffer with %d bytes when %d were expected\n",
buf_size, 48 + s->height * (s->width * 3 / 4));
return AVERROR_INVALIDDATA;
}
/* pixel data starts 48 bytes in, after 3x16-byte tables */
stream_ptr = 48;
if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) {
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
return ret;
}
y_plane = frame->data[0];
u_plane = frame->data[1];
v_plane = frame->data[2];
/* iterate through each line in the height */
for (y_ptr = 0, u_ptr = 0, v_ptr = 0;
y_ptr < (s->height * frame->linesize[0]);
y_ptr += frame->linesize[0] - s->width,
u_ptr += frame->linesize[1] - s->width / 4,
v_ptr += frame->linesize[2] - s->width / 4) {
/* reset predictors */
cur_byte = buf[stream_ptr++];
u_plane[u_ptr++] = u_pred = cur_byte & 0xF0;
y_plane[y_ptr++] = y_pred = (cur_byte & 0x0F) << 4;
cur_byte = buf[stream_ptr++];
v_plane[v_ptr++] = v_pred = cur_byte & 0xF0;
y_pred += y_table[cur_byte & 0x0F];
y_plane[y_ptr++] = y_pred;
cur_byte = buf[stream_ptr++];
y_pred += y_table[cur_byte & 0x0F];
y_plane[y_ptr++] = y_pred;
y_pred += y_table[(cur_byte & 0xF0) >> 4];
y_plane[y_ptr++] = y_pred;
/* iterate through the remaining pixel groups (4 pixels/group) */
pixel_groups = s->width / 4 - 1;
while (pixel_groups--) {
cur_byte = buf[stream_ptr++];
u_pred += u_table[(cur_byte & 0xF0) >> 4];
u_plane[u_ptr++] = u_pred;
y_pred += y_table[cur_byte & 0x0F];
y_plane[y_ptr++] = y_pred;
cur_byte = buf[stream_ptr++];
v_pred += v_table[(cur_byte & 0xF0) >> 4];
v_plane[v_ptr++] = v_pred;
y_pred += y_table[cur_byte & 0x0F];
y_plane[y_ptr++] = y_pred;
cur_byte = buf[stream_ptr++];
y_pred += y_table[cur_byte & 0x0F];
y_plane[y_ptr++] = y_pred;
y_pred += y_table[(cur_byte & 0xF0) >> 4];
y_plane[y_ptr++] = y_pred;
}
}
*got_frame = 1;
return buf_size;
}
#if CONFIG_AURA_DECODER
AVCodec ff_aura_decoder = {
.name = "aura",
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_AURA,
.priv_data_size = sizeof(CyuvDecodeContext),
.init = cyuv_decode_init,
.decode = cyuv_decode_frame,
.capabilities = CODEC_CAP_DR1,
.long_name = NULL_IF_CONFIG_SMALL("Auravision AURA"),
};
#endif
#if CONFIG_CYUV_DECODER
AVCodec ff_cyuv_decoder = {
.name = "cyuv",
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_CYUV,
.priv_data_size = sizeof(CyuvDecodeContext),
.init = cyuv_decode_init,
.decode = cyuv_decode_frame,
.capabilities = CODEC_CAP_DR1,
.long_name = NULL_IF_CONFIG_SMALL("Creative YUV (CYUV)"),
};
#endif
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