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FFmpeg/libavcodec/mwsc.c
Andreas Rheinhardt a247ac640d avcodec: Constify AVCodecs
Given that the AVCodec.next pointer has now been removed, most of the
AVCodecs are not modified at all any more and can therefore be made
const (as this patch does); the only exceptions are the very few codecs
for external libraries that have a init_static_data callback.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Signed-off-by: James Almer <jamrial@gmail.com>
2021-04-27 10:43:15 -03:00

193 lines
5.8 KiB
C

/*
* MatchWare Screen Capture Codec decoder
*
* Copyright (c) 2018 Paul B Mahol
*
* 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 <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "avcodec.h"
#include "bytestream.h"
#include "internal.h"
#include <zlib.h>
typedef struct MWSCContext {
unsigned int decomp_size;
uint8_t *decomp_buf;
z_stream zstream;
AVFrame *prev_frame;
} MWSCContext;
static int rle_uncompress(GetByteContext *gb, PutByteContext *pb, GetByteContext *gbp,
int width, int height, int stride, int pb_linesize, int gbp_linesize)
{
int intra = 1, w = 0;
bytestream2_seek_p(pb, (height - 1) * pb_linesize, SEEK_SET);
while (bytestream2_get_bytes_left(gb) > 0) {
uint32_t fill = bytestream2_get_le24(gb);
unsigned run = bytestream2_get_byte(gb);
if (run == 0) {
run = bytestream2_get_le32(gb);
for (int j = 0; j < run; j++, w++) {
if (w == width) {
w = 0;
bytestream2_seek_p(pb, -(pb_linesize + stride), SEEK_CUR);
}
bytestream2_put_le24(pb, fill);
}
} else if (run == 255) {
int pos = bytestream2_tell_p(pb);
bytestream2_seek(gbp, pos, SEEK_SET);
for (int j = 0; j < fill; j++, w++) {
if (w == width) {
w = 0;
bytestream2_seek_p(pb, -(pb_linesize + stride), SEEK_CUR);
bytestream2_seek(gbp, -(gbp_linesize + stride), SEEK_CUR);
}
bytestream2_put_le24(pb, bytestream2_get_le24(gbp));
}
intra = 0;
} else {
for (int j = 0; j < run; j++, w++) {
if (w == width) {
w = 0;
bytestream2_seek_p(pb, -(pb_linesize + stride), SEEK_CUR);
}
bytestream2_put_le24(pb, fill);
}
}
}
return intra;
}
static int decode_frame(AVCodecContext *avctx,
void *data, int *got_frame,
AVPacket *avpkt)
{
MWSCContext *s = avctx->priv_data;
AVFrame *frame = data;
uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
GetByteContext gb;
GetByteContext gbp;
PutByteContext pb;
int ret;
ret = inflateReset(&s->zstream);
if (ret != Z_OK) {
av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);
return AVERROR_EXTERNAL;
}
s->zstream.next_in = buf;
s->zstream.avail_in = buf_size;
s->zstream.next_out = s->decomp_buf;
s->zstream.avail_out = s->decomp_size;
ret = inflate(&s->zstream, Z_FINISH);
if (ret != Z_STREAM_END) {
av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", ret);
return AVERROR_EXTERNAL;
}
if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
return ret;
bytestream2_init(&gb, s->decomp_buf, s->zstream.total_out);
bytestream2_init(&gbp, s->prev_frame->data[0], avctx->height * s->prev_frame->linesize[0]);
bytestream2_init_writer(&pb, frame->data[0], avctx->height * frame->linesize[0]);
frame->key_frame = rle_uncompress(&gb, &pb, &gbp, avctx->width, avctx->height, avctx->width * 3,
frame->linesize[0], s->prev_frame->linesize[0]);
frame->pict_type = frame->key_frame ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
av_frame_unref(s->prev_frame);
if ((ret = av_frame_ref(s->prev_frame, frame)) < 0)
return ret;
*got_frame = 1;
return avpkt->size;
}
static av_cold int decode_init(AVCodecContext *avctx)
{
MWSCContext *s = avctx->priv_data;
int64_t size;
int zret;
avctx->pix_fmt = AV_PIX_FMT_BGR24;
size = 32LL * avctx->height * avctx->width;
if (size >= INT32_MAX)
return AVERROR_INVALIDDATA;
s->decomp_size = size;
if (!(s->decomp_buf = av_malloc(s->decomp_size)))
return AVERROR(ENOMEM);
s->zstream.zalloc = Z_NULL;
s->zstream.zfree = Z_NULL;
s->zstream.opaque = Z_NULL;
zret = inflateInit(&s->zstream);
if (zret != Z_OK) {
av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
return AVERROR_EXTERNAL;
}
s->prev_frame = av_frame_alloc();
if (!s->prev_frame)
return AVERROR(ENOMEM);
return 0;
}
static av_cold int decode_close(AVCodecContext *avctx)
{
MWSCContext *s = avctx->priv_data;
av_frame_free(&s->prev_frame);
av_freep(&s->decomp_buf);
s->decomp_size = 0;
inflateEnd(&s->zstream);
return 0;
}
const AVCodec ff_mwsc_decoder = {
.name = "mwsc",
.long_name = NULL_IF_CONFIG_SMALL("MatchWare Screen Capture Codec"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_MWSC,
.priv_data_size = sizeof(MWSCContext),
.init = decode_init,
.close = decode_close,
.decode = decode_frame,
.capabilities = AV_CODEC_CAP_DR1,
.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE |
FF_CODEC_CAP_INIT_CLEANUP,
};