| 1 | /* |
| 2 | * Silicon Graphics RLE 8-bit video decoder |
| 3 | * Copyright (c) 2012 Peter Ross |
| 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 | * Silicon Graphics RLE 8-bit video decoder |
| 25 | * @note Data is packed in rbg323 with rle, contained in mv or mov. |
| 26 | * The algorithm and pixfmt are subtly different from SGI images. |
| 27 | */ |
| 28 | |
| 29 | #include "libavutil/common.h" |
| 30 | |
| 31 | #include "avcodec.h" |
| 32 | #include "internal.h" |
| 33 | |
| 34 | typedef struct SGIRLEContext { |
| 35 | AVFrame *frame; |
| 36 | } SGIRLEContext; |
| 37 | |
| 38 | static av_cold int sgirle_decode_init(AVCodecContext *avctx) |
| 39 | { |
| 40 | SGIRLEContext *s = avctx->priv_data; |
| 41 | avctx->pix_fmt = AV_PIX_FMT_BGR8; |
| 42 | s->frame = av_frame_alloc(); |
| 43 | if (!s->frame) |
| 44 | return AVERROR(ENOMEM); |
| 45 | return 0; |
| 46 | } |
| 47 | |
| 48 | /** |
| 49 | * Convert SGI RBG323 pixel into AV_PIX_FMT_BGR8 |
| 50 | * SGI RGB data is packed as 8bpp, (msb)3R 2B 3G(lsb) |
| 51 | */ |
| 52 | #define RBG323_TO_BGR8(x) ((((x) << 3) & 0xC0) | \ |
| 53 | (((x) << 3) & 0x38) | \ |
| 54 | (((x) >> 5) & 7)) |
| 55 | static av_always_inline |
| 56 | void rbg323_to_bgr8(uint8_t *dst, const uint8_t *src, int size) |
| 57 | { |
| 58 | int i; |
| 59 | for (i = 0; i < size; i++) |
| 60 | dst[i] = RBG323_TO_BGR8(src[i]); |
| 61 | } |
| 62 | |
| 63 | /** |
| 64 | * @param[out] dst Destination buffer |
| 65 | * @param[in] src Source buffer |
| 66 | * @param src_size Source buffer size (bytes) |
| 67 | * @param width Width of destination buffer (pixels) |
| 68 | * @param height Height of destination buffer (pixels) |
| 69 | * @param linesize Line size of destination buffer (bytes) |
| 70 | * |
| 71 | * @return <0 on error |
| 72 | */ |
| 73 | static int decode_sgirle8(AVCodecContext *avctx, uint8_t *dst, |
| 74 | const uint8_t *src, int src_size, |
| 75 | int width, int height, ptrdiff_t linesize) |
| 76 | { |
| 77 | const uint8_t *src_end = src + src_size; |
| 78 | int x = 0, y = 0; |
| 79 | |
| 80 | #define INC_XY(n) \ |
| 81 | x += n; \ |
| 82 | if (x >= width) { \ |
| 83 | y++; \ |
| 84 | if (y >= height) \ |
| 85 | return 0; \ |
| 86 | x = 0; \ |
| 87 | } |
| 88 | |
| 89 | while (src_end - src >= 2) { |
| 90 | uint8_t v = *src++; |
| 91 | if (v > 0 && v < 0xC0) { |
| 92 | do { |
| 93 | int length = FFMIN(v, width - x); |
| 94 | if (length <= 0) |
| 95 | break; |
| 96 | memset(dst + y * linesize + x, RBG323_TO_BGR8(*src), length); |
| 97 | INC_XY(length); |
| 98 | v -= length; |
| 99 | } while (v > 0); |
| 100 | src++; |
| 101 | } else if (v >= 0xC1) { |
| 102 | v -= 0xC0; |
| 103 | do { |
| 104 | int length = FFMIN3(v, width - x, src_end - src); |
| 105 | if (src_end - src < length || length <= 0) |
| 106 | break; |
| 107 | rbg323_to_bgr8(dst + y * linesize + x, src, length); |
| 108 | INC_XY(length); |
| 109 | src += length; |
| 110 | v -= length; |
| 111 | } while (v > 0); |
| 112 | } else { |
| 113 | avpriv_request_sample(avctx, "opcode %d", v); |
| 114 | return AVERROR_PATCHWELCOME; |
| 115 | } |
| 116 | } |
| 117 | return 0; |
| 118 | } |
| 119 | |
| 120 | static int sgirle_decode_frame(AVCodecContext *avctx, void *data, |
| 121 | int *got_frame, AVPacket *avpkt) |
| 122 | { |
| 123 | SGIRLEContext *s = avctx->priv_data; |
| 124 | int ret; |
| 125 | |
| 126 | if ((ret = ff_reget_buffer(avctx, s->frame)) < 0) |
| 127 | return ret; |
| 128 | |
| 129 | ret = decode_sgirle8(avctx, s->frame->data[0], avpkt->data, avpkt->size, |
| 130 | avctx->width, avctx->height, s->frame->linesize[0]); |
| 131 | if (ret < 0) |
| 132 | return ret; |
| 133 | |
| 134 | *got_frame = 1; |
| 135 | if ((ret = av_frame_ref(data, s->frame)) < 0) |
| 136 | return ret; |
| 137 | |
| 138 | return avpkt->size; |
| 139 | } |
| 140 | |
| 141 | static av_cold int sgirle_decode_end(AVCodecContext *avctx) |
| 142 | { |
| 143 | SGIRLEContext *s = avctx->priv_data; |
| 144 | |
| 145 | av_frame_free(&s->frame); |
| 146 | |
| 147 | return 0; |
| 148 | } |
| 149 | |
| 150 | AVCodec ff_sgirle_decoder = { |
| 151 | .name = "sgirle", |
| 152 | .long_name = NULL_IF_CONFIG_SMALL("Silicon Graphics RLE 8-bit video"), |
| 153 | .type = AVMEDIA_TYPE_VIDEO, |
| 154 | .id = AV_CODEC_ID_SGIRLE, |
| 155 | .priv_data_size = sizeof(SGIRLEContext), |
| 156 | .init = sgirle_decode_init, |
| 157 | .close = sgirle_decode_end, |
| 158 | .decode = sgirle_decode_frame, |
| 159 | .capabilities = CODEC_CAP_DR1, |
| 160 | }; |