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/*
* SGI RLE 8-bit 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
* SGI RLE 8-bit decoder
*/
#include "libavutil/intreadwrite.h"
#include "avcodec.h"
#include "bytestream.h"
#include "internal.h"
typedef struct SGIRLEContext {
AVFrame *frame;
} SGIRLEContext;
static av_cold int sgirle_decode_init(AVCodecContext *avctx)
{
SGIRLEContext *s = avctx->priv_data;
avctx->pix_fmt = AV_PIX_FMT_BGR8;
s->frame = av_frame_alloc();
if (!s->frame)
return AVERROR(ENOMEM);
return 0;
}
/**
* Convert SGI RGB332 pixel into PIX_FMT_BGR8
* SGI RGB332 is packed RGB 3:3:2, 8bpp, (msb)3R 2B 3G(lsb)
*/
#define RGB332_TO_BGR8(x) (((x << 3) & 0xC0) | ((x << 3) & 0x38) | ((x >> 5) & 7))
static av_always_inline void memcpy_rgb332_to_bgr8(uint8_t *dst, const uint8_t *src, int size)
{
int i;
for (i = 0; i < size; i++)
dst[i] = RGB332_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, int 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);
memset(dst + y*linesize + x, RGB332_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)
break;
memcpy_rgb332_to_bgr8(dst + y*linesize + x, src, length);
INC_XY(length);
src += length;
v -= length;
} while (v > 0);
} else {
av_log_ask_for_sample(avctx, "unknown opcode\n");
return AVERROR_PATCHWELCOME;
}
}
return 0;
}
static int sgirle_decode_frame(AVCodecContext *avctx,
void *data, int *got_frame,
AVPacket *avpkt)
{
SGIRLEContext *s = avctx->priv_data;
int ret;
if ((ret = ff_reget_buffer(avctx, s->frame)) < 0)
return ret;
ret = decode_sgirle8(avctx, s->frame->data[0], avpkt->data, avpkt->size, avctx->width, avctx->height, s->frame->linesize[0]);
if (ret < 0)
return ret;
*got_frame = 1;
if ((ret = av_frame_ref(data, s->frame)) < 0)
return ret;
return avpkt->size;
}
static av_cold int sgirle_decode_end(AVCodecContext *avctx)
{
SGIRLEContext *s = avctx->priv_data;
av_frame_free(&s->frame);
return 0;
}
AVCodec ff_sgirle_decoder = {
.name = "sgirle",
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_SGIRLE,
.priv_data_size = sizeof(SGIRLEContext),
.init = sgirle_decode_init,
.close = sgirle_decode_end,
.decode = sgirle_decode_frame,
.capabilities = CODEC_CAP_DR1,
.long_name = NULL_IF_CONFIG_SMALL("SGI RLE 8-bit"),
};
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