ffmpeg/libavcodec/wbmpdec.c

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/*
* WBMP (Wireless Application Protocol Bitmap) image
*
* 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 "avcodec.h"
#include "bytestream.h"
#include "codec_internal.h"
#include "decode.h"
#include "thread.h"
static unsigned int getv(GetByteContext * gb)
{
int i;
unsigned int v = 0;
do {
i = bytestream2_get_byte(gb);
v = (v << 7) | (i & 0x7F);
} while (i & 0x80);
return v;
}
static void readbits(uint8_t * dst, int width, int height, int linesize, const uint8_t * src, int size)
{
int wpad = (width + 7) / 8;
for (int j = 0; j < height && size > 0; j++) {
memcpy(dst, src, FFMIN(wpad, size));
src += wpad;
size -= wpad;
dst += linesize;
}
}
static int wbmp_decode_frame(AVCodecContext *avctx, AVFrame *p,
int *got_frame, AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size, width, height, ret;
GetByteContext gb;
bytestream2_init(&gb, buf, buf_size);
if (getv(&gb))
return AVERROR_INVALIDDATA;
bytestream2_skip(&gb, 1);
width = getv(&gb);
height = getv(&gb);
if ((ret = ff_set_dimensions(avctx, width, height)) < 0)
return ret;
avctx->pix_fmt = AV_PIX_FMT_MONOBLACK;
if ((ret = ff_thread_get_buffer(avctx, p, 0)) < 0)
return ret;
if (p->linesize[0] == (width + 7) / 8)
bytestream2_get_buffer(&gb, p->data[0], height * ((width + 7) / 8));
else
readbits(p->data[0], width, height, p->linesize[0], gb.buffer, gb.buffer_end - gb.buffer);
p->key_frame = 1;
p->pict_type = AV_PICTURE_TYPE_I;
*got_frame = 1;
return buf_size;
}
const FFCodec ff_wbmp_decoder = {
.p.name = "wbmp",
CODEC_LONG_NAME("WBMP (Wireless Application Protocol Bitmap) image"),
.p.type = AVMEDIA_TYPE_VIDEO,
.p.id = AV_CODEC_ID_WBMP,
.p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
FF_CODEC_DECODE_CB(wbmp_decode_frame),
};