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165 lines
5.4 KiB
165 lines
5.4 KiB
/* |
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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 |
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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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* @see http://wiki.multimedia.cx/index.php?title=Bethsoft_VID |
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* @see http://www.svatopluk.com/andux/docs/dfvid.html |
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*/ |
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#include "libavutil/common.h" |
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#include "avcodec.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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GetByteContext g; |
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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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avcodec_get_frame_defaults(&vid->frame); |
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vid->frame.reference = 3; |
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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 = AV_PIX_FMT_PAL8; |
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return 0; |
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} |
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static int set_palette(BethsoftvidContext *ctx) |
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{ |
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uint32_t *palette = (uint32_t *)ctx->frame.data[1]; |
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int a; |
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if (bytestream2_get_bytes_left(&ctx->g) < 256*3) |
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return AVERROR_INVALIDDATA; |
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for(a = 0; a < 256; a++){ |
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palette[a] = 0xFFU << 24 | bytestream2_get_be24u(&ctx->g) * 4; |
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palette[a] |= palette[a] >> 6 & 0x30303; |
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} |
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ctx->frame.palette_has_changed = 1; |
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return 0; |
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} |
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static int bethsoftvid_decode_frame(AVCodecContext *avctx, |
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void *data, int *got_frame, |
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AVPacket *avpkt) |
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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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int wrap_to_next_line; |
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int code, ret; |
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int yoffset; |
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if ((ret = avctx->reget_buffer(avctx, &vid->frame)) < 0) { |
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av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n"); |
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return ret; |
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} |
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wrap_to_next_line = vid->frame.linesize[0] - avctx->width; |
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if (avpkt->side_data_elems > 0 && |
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avpkt->side_data[0].type == AV_PKT_DATA_PALETTE) { |
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bytestream2_init(&vid->g, avpkt->side_data[0].data, |
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avpkt->side_data[0].size); |
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if ((ret = set_palette(vid)) < 0) |
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return ret; |
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} |
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bytestream2_init(&vid->g, avpkt->data, avpkt->size); |
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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 = bytestream2_get_byte(&vid->g)){ |
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case PALETTE_BLOCK: { |
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*got_frame = 0; |
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if ((ret = set_palette(vid)) < 0) { |
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av_log(avctx, AV_LOG_ERROR, "error reading palette\n"); |
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return ret; |
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} |
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return bytestream2_tell(&vid->g); |
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} |
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case VIDEO_YOFF_P_FRAME: |
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yoffset = bytestream2_get_le16(&vid->g); |
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if(yoffset >= avctx->height) |
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return AVERROR_INVALIDDATA; |
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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 = bytestream2_get_byte(&vid->g))){ |
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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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bytestream2_get_buffer(&vid->g, dst, remaining); |
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else if(block_type == VIDEO_I_FRAME) |
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memset(dst, bytestream2_peek_byte(&vid->g), 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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bytestream2_get_buffer(&vid->g, dst, length); |
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else if(block_type == VIDEO_I_FRAME) |
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memset(dst, bytestream2_get_byte(&vid->g), 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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*got_frame = 1; |
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*(AVFrame*)data = vid->frame; |
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return avpkt->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 ff_bethsoftvid_decoder = { |
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.name = "bethsoftvid", |
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.type = AVMEDIA_TYPE_VIDEO, |
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.id = AV_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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.capabilities = CODEC_CAP_DR1, |
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.long_name = NULL_IF_CONFIG_SMALL("Bethesda VID video"), |
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};
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