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FFmpeg/libavcodec/bethsoftvideo.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

173 lines
5.4 KiB
C

/*
* Bethesda VID video decoder
* Copyright (C) 2007 Nicholas Tung
*
* 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
*/
/**
* @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] = 0xFFU << 24 | bytestream2_get_be24u(&ctx->g) * 4;
palette[a] |= palette[a] >> 6 & 0x30303;
}
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)) < 0)
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;
case VIDEO_P_FRAME:
case VIDEO_I_FRAME:
break;
default:
return AVERROR_INVALIDDATA;
}
// 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;
}
const 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 = AV_CODEC_CAP_DR1,
.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
};