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/*
* Bethesda VID video decoder
* Copyright (C) 2007 Nicholas Tung
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* @brief Bethesda Softworks VID Video Decoder
* @author Nicholas Tung [ntung (at. ntung com] (2007-03)
* @see http://wiki.multimedia.cx/index.php?title=Bethsoft_VID
* @see http://www.svatopluk.com/andux/docs/dfvid.html
*/
#include "libavutil/common.h"
#include "avcodec.h"
#include "bethsoftvideo.h"
#include "bytestream.h"
#include "internal.h"
typedef struct BethsoftvidContext {
AVFrame *frame;
GetByteContext g;
} BethsoftvidContext;
static av_cold int bethsoftvid_decode_init(AVCodecContext *avctx)
{
BethsoftvidContext *vid = avctx->priv_data;
avctx->pix_fmt = AV_PIX_FMT_PAL8;
vid->frame = av_frame_alloc();
if (!vid->frame)
return AVERROR(ENOMEM);
return 0;
}
static int set_palette(BethsoftvidContext *ctx)
{
uint32_t *palette = (uint32_t *)ctx->frame->data[1];
int a;
if (bytestream2_get_bytes_left(&ctx->g) < 256*3)
return AVERROR_INVALIDDATA;
for(a = 0; a < 256; a++){
palette[a] = bytestream2_get_be24u(&ctx->g) * 4;
}
ctx->frame->palette_has_changed = 1;
return 0;
}
static int bethsoftvid_decode_frame(AVCodecContext *avctx,
void *data, int *got_frame,
AVPacket *avpkt)
{
BethsoftvidContext * vid = avctx->priv_data;
char block_type;
uint8_t * dst;
uint8_t * frame_end;
int remaining = avctx->width; // number of bytes remaining on a line
int wrap_to_next_line;
int code, ret;
int yoffset;
if ((ret = ff_reget_buffer(avctx, vid->frame)) < 0) {
av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
return ret;
}
wrap_to_next_line = vid->frame->linesize[0] - avctx->width;
if (avpkt->side_data_elems > 0 &&
avpkt->side_data[0].type == AV_PKT_DATA_PALETTE) {
bytestream2_init(&vid->g, avpkt->side_data[0].data,
avpkt->side_data[0].size);
if ((ret = set_palette(vid)) < 0)
return ret;
}
bytestream2_init(&vid->g, avpkt->data, avpkt->size);
dst = vid->frame->data[0];
frame_end = vid->frame->data[0] + vid->frame->linesize[0] * avctx->height;
switch(block_type = bytestream2_get_byte(&vid->g)){
case PALETTE_BLOCK: {
*got_frame = 0;
if ((ret = set_palette(vid)) < 0) {
av_log(avctx, AV_LOG_ERROR, "error reading palette\n");
return ret;
}
return bytestream2_tell(&vid->g);
}
case VIDEO_YOFF_P_FRAME:
yoffset = bytestream2_get_le16(&vid->g);
if(yoffset >= avctx->height)
return AVERROR_INVALIDDATA;
dst += vid->frame->linesize[0] * yoffset;
}
// main code
while((code = bytestream2_get_byte(&vid->g))){
int length = code & 0x7f;
// copy any bytes starting at the current position, and ending at the frame width
while(length > remaining){
if(code < 0x80)
bytestream2_get_buffer(&vid->g, dst, remaining);
else if(block_type == VIDEO_I_FRAME)
memset(dst, bytestream2_peek_byte(&vid->g), remaining);
length -= remaining; // decrement the number of bytes to be copied
dst += remaining + wrap_to_next_line; // skip over extra bytes at end of frame
remaining = avctx->width;
if(dst == frame_end)
goto end;
}
// copy any remaining bytes after / if line overflows
if(code < 0x80)
bytestream2_get_buffer(&vid->g, dst, length);
else if(block_type == VIDEO_I_FRAME)
memset(dst, bytestream2_get_byte(&vid->g), length);
remaining -= length;
dst += length;
}
end:
if ((ret = av_frame_ref(data, vid->frame)) < 0)
return ret;
*got_frame = 1;
return avpkt->size;
}
static av_cold int bethsoftvid_decode_end(AVCodecContext *avctx)
{
BethsoftvidContext * vid = avctx->priv_data;
av_frame_free(&vid->frame);
return 0;
}
AVCodec ff_bethsoftvid_decoder = {
.name = "bethsoftvid",
.long_name = NULL_IF_CONFIG_SMALL("Bethesda VID video"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_BETHSOFTVID,
.priv_data_size = sizeof(BethsoftvidContext),
.init = bethsoftvid_decode_init,
.close = bethsoftvid_decode_end,
.decode = bethsoftvid_decode_frame,
.capabilities = CODEC_CAP_DR1,
};
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