| 1 | /* |
| 2 | * Alias PIX image decoder |
| 3 | * Copyright (C) 2014 Vittorio Giovara <vittorio.giovara@gmail.com> |
| 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 | #include "libavutil/intreadwrite.h" |
| 23 | |
| 24 | #include "avcodec.h" |
| 25 | #include "bytestream.h" |
| 26 | #include "internal.h" |
| 27 | |
| 28 | #define ALIAS_HEADER_SIZE 10 |
| 29 | |
| 30 | static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, |
| 31 | AVPacket *avpkt) |
| 32 | { |
| 33 | AVFrame *f = data; |
| 34 | GetByteContext gb; |
| 35 | int width, height, ret, bits_pixel, pixel; |
| 36 | uint8_t *out_buf; |
| 37 | uint8_t count; |
| 38 | int x, y; |
| 39 | |
| 40 | bytestream2_init(&gb, avpkt->data, avpkt->size); |
| 41 | |
| 42 | if (bytestream2_get_bytes_left(&gb) < ALIAS_HEADER_SIZE) { |
| 43 | av_log(avctx, AV_LOG_ERROR, "Header too small %d.\n", avpkt->size); |
| 44 | return AVERROR_INVALIDDATA; |
| 45 | } |
| 46 | |
| 47 | width = bytestream2_get_be16u(&gb); |
| 48 | height = bytestream2_get_be16u(&gb); |
| 49 | bytestream2_skipu(&gb, 4); // obsolete X, Y offset |
| 50 | bits_pixel = bytestream2_get_be16u(&gb); |
| 51 | |
| 52 | if (bits_pixel == 24) |
| 53 | avctx->pix_fmt = AV_PIX_FMT_BGR24; |
| 54 | else if (bits_pixel == 8) |
| 55 | avctx->pix_fmt = AV_PIX_FMT_GRAY8; |
| 56 | else { |
| 57 | av_log(avctx, AV_LOG_ERROR, "Invalid pixel format.\n"); |
| 58 | return AVERROR_INVALIDDATA; |
| 59 | } |
| 60 | |
| 61 | ret = ff_set_dimensions(avctx, width, height); |
| 62 | if (ret < 0) |
| 63 | return ret; |
| 64 | |
| 65 | ret = ff_get_buffer(avctx, f, 0); |
| 66 | if (ret < 0) |
| 67 | return ret; |
| 68 | |
| 69 | f->pict_type = AV_PICTURE_TYPE_I; |
| 70 | f->key_frame = 1; |
| 71 | |
| 72 | x = 0; |
| 73 | y = 1; |
| 74 | out_buf = f->data[0]; |
| 75 | while (bytestream2_get_bytes_left(&gb) > 0) { |
| 76 | int i; |
| 77 | |
| 78 | /* set buffer at the right position at every new line */ |
| 79 | if (x == avctx->width) { |
| 80 | x = 0; |
| 81 | out_buf = f->data[0] + f->linesize[0] * y++; |
| 82 | if (y > avctx->height) { |
| 83 | av_log(avctx, AV_LOG_ERROR, |
| 84 | "Ended frame decoding with %d bytes left.\n", |
| 85 | bytestream2_get_bytes_left(&gb)); |
| 86 | return AVERROR_INVALIDDATA; |
| 87 | } |
| 88 | } |
| 89 | |
| 90 | /* read packet and copy data */ |
| 91 | count = bytestream2_get_byteu(&gb); |
| 92 | if (!count || x + count > avctx->width) { |
| 93 | av_log(avctx, AV_LOG_ERROR, "Invalid run length %d.\n", count); |
| 94 | return AVERROR_INVALIDDATA; |
| 95 | } |
| 96 | |
| 97 | if (avctx->pix_fmt == AV_PIX_FMT_BGR24) { |
| 98 | pixel = bytestream2_get_be24(&gb); |
| 99 | for (i = 0; i < count; i++) { |
| 100 | AV_WB24(out_buf, pixel); |
| 101 | out_buf += 3; |
| 102 | } |
| 103 | } else { // AV_PIX_FMT_GRAY8 |
| 104 | pixel = bytestream2_get_byte(&gb); |
| 105 | for (i = 0; i < count; i++) |
| 106 | *out_buf++ = pixel; |
| 107 | } |
| 108 | |
| 109 | x += i; |
| 110 | } |
| 111 | |
| 112 | if (x != width || y != height) { |
| 113 | av_log(avctx, AV_LOG_ERROR, "Picture stopped at %d,%d.\n", x, y); |
| 114 | return AVERROR_INVALIDDATA; |
| 115 | } |
| 116 | |
| 117 | *got_frame = 1; |
| 118 | return avpkt->size; |
| 119 | } |
| 120 | |
| 121 | AVCodec ff_alias_pix_decoder = { |
| 122 | .name = "alias_pix", |
| 123 | .long_name = NULL_IF_CONFIG_SMALL("Alias/Wavefront PIX image"), |
| 124 | .type = AVMEDIA_TYPE_VIDEO, |
| 125 | .id = AV_CODEC_ID_ALIAS_PIX, |
| 126 | .decode = decode_frame, |
| 127 | .capabilities = CODEC_CAP_DR1, |
| 128 | }; |