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/*
* Alias PIX image encoder
* Copyright (C) 2014 Vittorio Giovara <vittorio.giovara@gmail.com>
*
* 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
*/
#include "libavutil/intreadwrite.h"
#include "avcodec.h"
#include "bytestream.h"
#include "encode.h"
#define ALIAS_HEADER_SIZE 10
static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
const AVFrame *frame, int *got_packet)
{
int width, height, bits_pixel, length, ret;
uint8_t *buf;
width = avctx->width;
height = avctx->height;
if (width > 65535 || height > 65535 ||
width * height >= INT_MAX / 4 - ALIAS_HEADER_SIZE) {
av_log(avctx, AV_LOG_ERROR, "Invalid image size %dx%d.\n", width, height);
return AVERROR_INVALIDDATA;
}
switch (avctx->pix_fmt) {
case AV_PIX_FMT_GRAY8:
bits_pixel = 8;
break;
case AV_PIX_FMT_BGR24:
bits_pixel = 24;
break;
default:
return AVERROR(EINVAL);
}
length = ALIAS_HEADER_SIZE + 4 * width * height; // max possible
if ((ret = ff_alloc_packet(avctx, pkt, length)) < 0)
return ret;
buf = pkt->data;
/* Encode header. */
bytestream_put_be16(&buf, width);
bytestream_put_be16(&buf, height);
bytestream_put_be32(&buf, 0); /* X, Y offset */
bytestream_put_be16(&buf, bits_pixel);
for (int j = 0, bytes_pixel = bits_pixel >> 3; j < height; j++) {
const uint8_t *in_buf = frame->data[0] + frame->linesize[0] * j;
const uint8_t *const line_end = in_buf + bytes_pixel * width;
while (in_buf < line_end) {
int count = 0;
int pixel;
if (avctx->pix_fmt == AV_PIX_FMT_GRAY8) {
pixel = *in_buf;
while (count < 255 && in_buf < line_end && pixel == *in_buf) {
count++;
in_buf++;
}
bytestream_put_byte(&buf, count);
bytestream_put_byte(&buf, pixel);
} else { /* AV_PIX_FMT_BGR24 */
pixel = AV_RB24(in_buf);
while (count < 255 && in_buf < line_end &&
pixel == AV_RB24(in_buf)) {
count++;
in_buf += 3;
}
bytestream_put_byte(&buf, count);
bytestream_put_be24(&buf, pixel);
}
}
}
/* Total length */
av_shrink_packet(pkt, buf - pkt->data);
*got_packet = 1;
return 0;
}
const AVCodec ff_alias_pix_encoder = {
.name = "alias_pix",
.long_name = NULL_IF_CONFIG_SMALL("Alias/Wavefront PIX image"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_ALIAS_PIX,
.encode2 = encode_frame,
.pix_fmts = (const enum AVPixelFormat[]) {
AV_PIX_FMT_BGR24, AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE
},
};
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