/*
* WinCAM Motion Video 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 "libavutil/imgutils.h"
#include "avcodec.h"
#include "bytestream.h"
#include "codec_internal.h"
#include "decode.h"
#include "zlib_wrapper.h"
#include <zlib.h>
typedef struct WCMVContext {
int bpp;
FFZStream zstream;
AVFrame *prev_frame;
uint8_t block_data[65536*8];
} WCMVContext;
static int decode_frame(AVCodecContext *avctx, AVFrame *frame,
int *got_frame, AVPacket *avpkt)
{
WCMVContext *s = avctx->priv_data;
z_stream *const zstream = &s->zstream.zstream;
int skip, blocks, zret, ret, intra = 0, flags = 0, bpp = s->bpp;
GetByteContext gb;
uint8_t *dst;
ret = inflateReset(zstream);
if (ret != Z_OK) {
av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);
return AVERROR_EXTERNAL;
}
bytestream2_init(&gb, avpkt->data, avpkt->size);
blocks = bytestream2_get_le16(&gb);
if (!blocks)
flags |= FF_REGET_BUFFER_FLAG_READONLY;
if ((ret = ff_reget_buffer(avctx, s->prev_frame, flags)) < 0)
return ret;
if (blocks > 5) {
GetByteContext bgb;
int x = 0, size;
if (blocks * 8 >= 0xFFFF)
size = bytestream2_get_le24(&gb);
else if (blocks * 8 >= 0xFF)
size = bytestream2_get_le16(&gb);
else
size = bytestream2_get_byte(&gb);
skip = bytestream2_tell(&gb);
if (size > avpkt->size - skip)
return AVERROR_INVALIDDATA;
zstream->next_in = avpkt->data + skip;
zstream->avail_in = size;
zstream->next_out = s->block_data;
zstream->avail_out = sizeof(s->block_data);
zret = inflate(zstream, Z_FINISH);
if (zret != Z_STREAM_END) {
av_log(avctx, AV_LOG_ERROR,
"Inflate failed with return code: %d.\n", zret);
return AVERROR_INVALIDDATA;
}
ret = inflateReset(zstream);
if (ret != Z_OK) {
av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);
return AVERROR_EXTERNAL;
}
bytestream2_skip(&gb, size);
bytestream2_init(&bgb, s->block_data, blocks * 8);
for (int i = 0; i < blocks; i++) {
int w, h;
bytestream2_skip(&bgb, 4);
w = bytestream2_get_le16(&bgb);
h = bytestream2_get_le16(&bgb);
if (x + bpp * (int64_t)w * h > INT_MAX)
return AVERROR_INVALIDDATA;
x += bpp * w * h;
}
if (x >= 0xFFFF)
bytestream2_skip(&gb, 3);
else if (x >= 0xFF)
bytestream2_skip(&gb, 2);
else
bytestream2_skip(&gb, 1);
skip = bytestream2_tell(&gb);
zstream->next_in = avpkt->data + skip;
zstream->avail_in = avpkt->size - skip;
bytestream2_init(&gb, s->block_data, blocks * 8);
} else if (blocks) {
int x = 0;
bytestream2_seek(&gb, 2, SEEK_SET);
for (int i = 0; i < blocks; i++) {
int w, h;
bytestream2_skip(&gb, 4);
w = bytestream2_get_le16(&gb);
h = bytestream2_get_le16(&gb);
if (x + bpp * (int64_t)w * h > INT_MAX)
return AVERROR_INVALIDDATA;
x += bpp * w * h;
}
if (x >= 0xFFFF)
bytestream2_skip(&gb, 3);
else if (x >= 0xFF)
bytestream2_skip(&gb, 2);
else
bytestream2_skip(&gb, 1);
skip = bytestream2_tell(&gb);
zstream->next_in = avpkt->data + skip;
zstream->avail_in = avpkt->size - skip;
bytestream2_seek(&gb, 2, SEEK_SET);
}
if (bytestream2_get_bytes_left(&gb) < 8LL * blocks)
return AVERROR_INVALIDDATA;
if (!avctx->frame_num) {
ptrdiff_t linesize[4] = { s->prev_frame->linesize[0], 0, 0, 0 };
av_image_fill_black(s->prev_frame->data, linesize, avctx->pix_fmt, 0,
avctx->width, avctx->height);
}
for (int block = 0; block < blocks; block++) {
int x, y, w, h;
x = bytestream2_get_le16(&gb);
y = bytestream2_get_le16(&gb);
w = bytestream2_get_le16(&gb);
h = bytestream2_get_le16(&gb);
if (blocks == 1 && x == 0 && y == 0 && w == avctx->width && h == avctx->height)
intra = 1;
if (x + w > avctx->width || y + h > avctx->height)
return AVERROR_INVALIDDATA;
if (w > avctx->width || h > avctx->height)
return AVERROR_INVALIDDATA;
dst = s->prev_frame->data[0] + (avctx->height - y - 1) * s->prev_frame->linesize[0] + x * bpp;
for (int i = 0; i < h; i++) {
zstream->next_out = dst;
zstream->avail_out = w * bpp;
zret = inflate(zstream, Z_SYNC_FLUSH);
if (zret != Z_OK && zret != Z_STREAM_END) {
av_log(avctx, AV_LOG_ERROR,
"Inflate failed with return code: %d.\n", zret);
return AVERROR_INVALIDDATA;
}
dst -= s->prev_frame->linesize[0];
}
}
if (intra)
s->prev_frame->flags |= AV_FRAME_FLAG_KEY;
else
s->prev_frame->flags &= ~AV_FRAME_FLAG_KEY;
s->prev_frame->pict_type = intra ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
if ((ret = av_frame_ref(frame, s->prev_frame)) < 0)
return ret;
*got_frame = 1;
return avpkt->size;
}
static av_cold int decode_init(AVCodecContext *avctx)
{
WCMVContext *s = avctx->priv_data;
switch (avctx->bits_per_coded_sample) {
case 16: avctx->pix_fmt = AV_PIX_FMT_RGB565LE; break;
case 24: avctx->pix_fmt = AV_PIX_FMT_BGR24; break;
case 32: avctx->pix_fmt = AV_PIX_FMT_BGRA; break;
default: av_log(avctx, AV_LOG_ERROR, "Unsupported bits_per_coded_sample: %d\n",
avctx->bits_per_coded_sample);
return AVERROR_PATCHWELCOME;
}
s->bpp = avctx->bits_per_coded_sample >> 3;
s->prev_frame = av_frame_alloc();
if (!s->prev_frame)
return AVERROR(ENOMEM);
return ff_inflate_init(&s->zstream, avctx);
}
static av_cold int decode_close(AVCodecContext *avctx)
{
WCMVContext *s = avctx->priv_data;
av_frame_free(&s->prev_frame);
ff_inflate_end(&s->zstream);
return 0;
}
const FFCodec ff_wcmv_decoder = {
.p.name = "wcmv",
CODEC_LONG_NAME("WinCAM Motion Video"),
.p.type = AVMEDIA_TYPE_VIDEO,
.p.id = AV_CODEC_ID_WCMV,
.priv_data_size = sizeof(WCMVContext),
.init = decode_init,
.close = decode_close,
FF_CODEC_DECODE_CB(decode_frame),
.p.capabilities = AV_CODEC_CAP_DR1,
.caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
};