/* * 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)        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   = AV_CODEC_CAP_DR1,    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,};