/*
* Silicon Graphics RLE 8-bit video decoder
* Copyright (c) 2012 Peter Ross
*
* This file is part of FFmpeg.
*
* FFmpeg 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.
*
* FFmpeg 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 FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* Silicon Graphics RLE 8-bit video decoder
* @note Data is packed in rbg323 with rle, contained in mv or mov.
* The algorithm and pixfmt are subtly different from SGI images.
*/
#include "libavutil/common.h"
#include "avcodec.h"
#include "internal.h"
static av_cold int sgirle_decode_init(AVCodecContext *avctx)
{
avctx->pix_fmt = AV_PIX_FMT_BGR8;
return 0;
}
/**
* Convert SGI RBG323 pixel into AV_PIX_FMT_BGR8
* SGI RGB data is packed as 8bpp, (msb)3R 2B 3G(lsb)
*/
#define RBG323_TO_BGR8(x) ((((x) << 3) & 0xC0) | \
(((x) << 3) & 0x38) | \
(((x) >> 5) & 7))
static av_always_inline
void rbg323_to_bgr8(uint8_t *dst, const uint8_t *src, int size)
{
int i;
for (i = 0; i < size; i++)
dst[i] = RBG323_TO_BGR8(src[i]);
}
/**
* @param[out] dst Destination buffer
* @param[in] src Source buffer
* @param src_size Source buffer size (bytes)
* @param width Width of destination buffer (pixels)
* @param height Height of destination buffer (pixels)
* @param linesize Line size of destination buffer (bytes)
*
* @return <0 on error
*/
static int decode_sgirle8(AVCodecContext *avctx, uint8_t *dst,
const uint8_t *src, int src_size,
int width, int height, ptrdiff_t linesize)
{
const uint8_t *src_end = src + src_size;
int x = 0, y = 0;
#define INC_XY(n) \
x += n; \
if (x >= width) { \
y++; \
if (y >= height) \
return 0; \
x = 0; \
}
while (src_end - src >= 2) {
uint8_t v = *src++;
if (v > 0 && v < 0xC0) {
do {
int length = FFMIN(v, width - x);
if (length <= 0)
break;
memset(dst + y * linesize + x, RBG323_TO_BGR8(*src), length);
INC_XY(length);
v -= length;
} while (v > 0);
src++;
} else if (v >= 0xC1) {
v -= 0xC0;
do {
int length = FFMIN3(v, width - x, src_end - src);
if (src_end - src < length || length <= 0)
break;
rbg323_to_bgr8(dst + y * linesize + x, src, length);
INC_XY(length);
src += length;
v -= length;
} while (v > 0);
} else {
avpriv_request_sample(avctx, "opcode %d", v);
return AVERROR_PATCHWELCOME;
}
}
return 0;
}
static int sgirle_decode_frame(AVCodecContext *avctx, void *data,
int *got_frame, AVPacket *avpkt)
{
AVFrame *frame = data;
int ret;
if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
return ret;
ret = decode_sgirle8(avctx, frame->data[0], avpkt->data, avpkt->size,
avctx->width, avctx->height, frame->linesize[0]);
if (ret < 0)
return ret;
frame->pict_type = AV_PICTURE_TYPE_I;
frame->key_frame = 1;
*got_frame = 1;
return avpkt->size;
}
AVCodec ff_sgirle_decoder = {
.name = "sgirle",
.long_name = NULL_IF_CONFIG_SMALL("Silicon Graphics RLE 8-bit video"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_SGIRLE,
.init = sgirle_decode_init,
.decode = sgirle_decode_frame,
.capabilities = AV_CODEC_CAP_DR1,
};