| 1 | /* |
| 2 | * Bethesda VID video decoder |
| 3 | * Copyright (C) 2007 Nicholas Tung |
| 4 | * |
| 5 | * This file is part of FFmpeg. |
| 6 | * |
| 7 | * FFmpeg is free software; you can redistribute it and/or |
| 8 | * modify it under the terms of the GNU Lesser General Public |
| 9 | * License as published by the Free Software Foundation; either |
| 10 | * version 2.1 of the License, or (at your option) any later version. |
| 11 | * |
| 12 | * FFmpeg is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 15 | * Lesser General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU Lesser General Public |
| 18 | * License along with FFmpeg; if not, write to the Free Software |
| 19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 20 | */ |
| 21 | |
| 22 | /** |
| 23 | * @file |
| 24 | * @brief Bethesda Softworks VID Video Decoder |
| 25 | * @author Nicholas Tung [ntung (at. ntung com] (2007-03) |
| 26 | * @see http://wiki.multimedia.cx/index.php?title=Bethsoft_VID |
| 27 | * @see http://www.svatopluk.com/andux/docs/dfvid.html |
| 28 | */ |
| 29 | |
| 30 | #include "libavutil/common.h" |
| 31 | #include "avcodec.h" |
| 32 | #include "bethsoftvideo.h" |
| 33 | #include "bytestream.h" |
| 34 | #include "internal.h" |
| 35 | |
| 36 | typedef struct BethsoftvidContext { |
| 37 | AVFrame *frame; |
| 38 | GetByteContext g; |
| 39 | } BethsoftvidContext; |
| 40 | |
| 41 | static av_cold int bethsoftvid_decode_init(AVCodecContext *avctx) |
| 42 | { |
| 43 | BethsoftvidContext *vid = avctx->priv_data; |
| 44 | avctx->pix_fmt = AV_PIX_FMT_PAL8; |
| 45 | |
| 46 | vid->frame = av_frame_alloc(); |
| 47 | if (!vid->frame) |
| 48 | return AVERROR(ENOMEM); |
| 49 | |
| 50 | return 0; |
| 51 | } |
| 52 | |
| 53 | static int set_palette(BethsoftvidContext *ctx) |
| 54 | { |
| 55 | uint32_t *palette = (uint32_t *)ctx->frame->data[1]; |
| 56 | int a; |
| 57 | |
| 58 | if (bytestream2_get_bytes_left(&ctx->g) < 256*3) |
| 59 | return AVERROR_INVALIDDATA; |
| 60 | |
| 61 | for(a = 0; a < 256; a++){ |
| 62 | palette[a] = 0xFFU << 24 | bytestream2_get_be24u(&ctx->g) * 4; |
| 63 | palette[a] |= palette[a] >> 6 & 0x30303; |
| 64 | } |
| 65 | ctx->frame->palette_has_changed = 1; |
| 66 | return 0; |
| 67 | } |
| 68 | |
| 69 | static int bethsoftvid_decode_frame(AVCodecContext *avctx, |
| 70 | void *data, int *got_frame, |
| 71 | AVPacket *avpkt) |
| 72 | { |
| 73 | BethsoftvidContext * vid = avctx->priv_data; |
| 74 | char block_type; |
| 75 | uint8_t * dst; |
| 76 | uint8_t * frame_end; |
| 77 | int remaining = avctx->width; // number of bytes remaining on a line |
| 78 | int wrap_to_next_line; |
| 79 | int code, ret; |
| 80 | int yoffset; |
| 81 | |
| 82 | if ((ret = ff_reget_buffer(avctx, vid->frame)) < 0) |
| 83 | return ret; |
| 84 | wrap_to_next_line = vid->frame->linesize[0] - avctx->width; |
| 85 | |
| 86 | if (avpkt->side_data_elems > 0 && |
| 87 | avpkt->side_data[0].type == AV_PKT_DATA_PALETTE) { |
| 88 | bytestream2_init(&vid->g, avpkt->side_data[0].data, |
| 89 | avpkt->side_data[0].size); |
| 90 | if ((ret = set_palette(vid)) < 0) |
| 91 | return ret; |
| 92 | } |
| 93 | |
| 94 | bytestream2_init(&vid->g, avpkt->data, avpkt->size); |
| 95 | dst = vid->frame->data[0]; |
| 96 | frame_end = vid->frame->data[0] + vid->frame->linesize[0] * avctx->height; |
| 97 | |
| 98 | switch(block_type = bytestream2_get_byte(&vid->g)){ |
| 99 | case PALETTE_BLOCK: { |
| 100 | *got_frame = 0; |
| 101 | if ((ret = set_palette(vid)) < 0) { |
| 102 | av_log(avctx, AV_LOG_ERROR, "error reading palette\n"); |
| 103 | return ret; |
| 104 | } |
| 105 | return bytestream2_tell(&vid->g); |
| 106 | } |
| 107 | case VIDEO_YOFF_P_FRAME: |
| 108 | yoffset = bytestream2_get_le16(&vid->g); |
| 109 | if(yoffset >= avctx->height) |
| 110 | return AVERROR_INVALIDDATA; |
| 111 | dst += vid->frame->linesize[0] * yoffset; |
| 112 | } |
| 113 | |
| 114 | // main code |
| 115 | while((code = bytestream2_get_byte(&vid->g))){ |
| 116 | int length = code & 0x7f; |
| 117 | |
| 118 | // copy any bytes starting at the current position, and ending at the frame width |
| 119 | while(length > remaining){ |
| 120 | if(code < 0x80) |
| 121 | bytestream2_get_buffer(&vid->g, dst, remaining); |
| 122 | else if(block_type == VIDEO_I_FRAME) |
| 123 | memset(dst, bytestream2_peek_byte(&vid->g), remaining); |
| 124 | length -= remaining; // decrement the number of bytes to be copied |
| 125 | dst += remaining + wrap_to_next_line; // skip over extra bytes at end of frame |
| 126 | remaining = avctx->width; |
| 127 | if(dst == frame_end) |
| 128 | goto end; |
| 129 | } |
| 130 | |
| 131 | // copy any remaining bytes after / if line overflows |
| 132 | if(code < 0x80) |
| 133 | bytestream2_get_buffer(&vid->g, dst, length); |
| 134 | else if(block_type == VIDEO_I_FRAME) |
| 135 | memset(dst, bytestream2_get_byte(&vid->g), length); |
| 136 | remaining -= length; |
| 137 | dst += length; |
| 138 | } |
| 139 | end: |
| 140 | |
| 141 | if ((ret = av_frame_ref(data, vid->frame)) < 0) |
| 142 | return ret; |
| 143 | |
| 144 | *got_frame = 1; |
| 145 | |
| 146 | return avpkt->size; |
| 147 | } |
| 148 | |
| 149 | static av_cold int bethsoftvid_decode_end(AVCodecContext *avctx) |
| 150 | { |
| 151 | BethsoftvidContext * vid = avctx->priv_data; |
| 152 | av_frame_free(&vid->frame); |
| 153 | return 0; |
| 154 | } |
| 155 | |
| 156 | AVCodec ff_bethsoftvid_decoder = { |
| 157 | .name = "bethsoftvid", |
| 158 | .long_name = NULL_IF_CONFIG_SMALL("Bethesda VID video"), |
| 159 | .type = AVMEDIA_TYPE_VIDEO, |
| 160 | .id = AV_CODEC_ID_BETHSOFTVID, |
| 161 | .priv_data_size = sizeof(BethsoftvidContext), |
| 162 | .init = bethsoftvid_decode_init, |
| 163 | .close = bethsoftvid_decode_end, |
| 164 | .decode = bethsoftvid_decode_frame, |
| 165 | .capabilities = CODEC_CAP_DR1, |
| 166 | }; |