140 lines
4.4 KiB
C
140 lines
4.4 KiB
C
/*
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* Bethesda VID video decoder
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* Copyright (C) 2007 Nicholas Tung
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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/**
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* @file bethsoftvideo.c
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* @brief Bethesda Softworks VID Video Decoder
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* @author Nicholas Tung [ntung (at. ntung com] (2007-03)
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* @sa http://wiki.multimedia.cx/index.php?title=Bethsoft_VID
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* @sa http://www.svatopluk.com/andux/docs/dfvid.html
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*/
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#include "common.h"
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#include "dsputil.h"
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#include "bethsoftvideo.h"
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#include "bytestream.h"
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typedef struct BethsoftvidContext {
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AVFrame frame;
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} BethsoftvidContext;
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static av_cold int bethsoftvid_decode_init(AVCodecContext *avctx)
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{
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BethsoftvidContext *vid = avctx->priv_data;
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vid->frame.reference = 1;
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vid->frame.buffer_hints = FF_BUFFER_HINTS_VALID |
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FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
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avctx->pix_fmt = PIX_FMT_PAL8;
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return 0;
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}
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static void set_palette(AVFrame * frame, const uint8_t * palette_buffer)
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{
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uint32_t * palette = (uint32_t *)frame->data[1];
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int a;
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for(a = 0; a < 256; a++){
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palette[a] = AV_RB24(&palette_buffer[a * 3]) * 4;
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}
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frame->palette_has_changed = 1;
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}
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static int bethsoftvid_decode_frame(AVCodecContext *avctx,
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void *data, int *data_size,
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const uint8_t *buf, int buf_size)
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{
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BethsoftvidContext * vid = avctx->priv_data;
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char block_type;
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uint8_t * dst;
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uint8_t * frame_end;
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int remaining = avctx->width; // number of bytes remaining on a line
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const int wrap_to_next_line = vid->frame.linesize[0] - avctx->width;
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int code;
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int yoffset;
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if (avctx->reget_buffer(avctx, &vid->frame)) {
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av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
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return -1;
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}
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dst = vid->frame.data[0];
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frame_end = vid->frame.data[0] + vid->frame.linesize[0] * avctx->height;
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switch(block_type = *buf++){
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case PALETTE_BLOCK:
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set_palette(&vid->frame, buf);
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return 0;
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case VIDEO_YOFF_P_FRAME:
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yoffset = bytestream_get_le16(&buf);
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if(yoffset >= avctx->height)
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return -1;
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dst += vid->frame.linesize[0] * yoffset;
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}
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// main code
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while((code = *buf++)){
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int length = code & 0x7f;
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// copy any bytes starting at the current position, and ending at the frame width
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while(length > remaining){
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if(code < 0x80)
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bytestream_get_buffer(&buf, dst, remaining);
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else if(block_type == VIDEO_I_FRAME)
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memset(dst, buf[0], remaining);
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length -= remaining; // decrement the number of bytes to be copied
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dst += remaining + wrap_to_next_line; // skip over extra bytes at end of frame
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remaining = avctx->width;
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if(dst == frame_end)
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goto end;
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}
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// copy any remaining bytes after / if line overflows
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if(code < 0x80)
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bytestream_get_buffer(&buf, dst, length);
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else if(block_type == VIDEO_I_FRAME)
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memset(dst, *buf++, length);
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remaining -= length;
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dst += length;
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}
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end:
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*data_size = sizeof(AVFrame);
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*(AVFrame*)data = vid->frame;
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return buf_size;
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}
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static av_cold int bethsoftvid_decode_end(AVCodecContext *avctx)
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{
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BethsoftvidContext * vid = avctx->priv_data;
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if(vid->frame.data[0])
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avctx->release_buffer(avctx, &vid->frame);
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return 0;
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}
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AVCodec bethsoftvid_decoder = {
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.name = "bethsoftvid",
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.type = CODEC_TYPE_VIDEO,
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.id = CODEC_ID_BETHSOFTVID,
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.priv_data_size = sizeof(BethsoftvidContext),
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.init = bethsoftvid_decode_init,
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.close = bethsoftvid_decode_end,
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.decode = bethsoftvid_decode_frame,
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};
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