| 1 | /* |
| 2 | * CPiA video decoder. |
| 3 | * Copyright (c) 2010 Hans de Goede <hdegoede@redhat.com> |
| 4 | * |
| 5 | * This decoder is based on the LGPL code available at |
| 6 | * https://v4l4j.googlecode.com/svn/v4l4j/trunk/libvideo/libv4lconvert/cpia1.c |
| 7 | * |
| 8 | * This file is part of FFmpeg. |
| 9 | * |
| 10 | * FFmpeg is free software; you can redistribute it and/or |
| 11 | * modify it under the terms of the GNU Lesser General Public |
| 12 | * License as published by the Free Software Foundation; either |
| 13 | * version 2.1 of the License, or (at your option) any later version. |
| 14 | * |
| 15 | * FFmpeg is distributed in the hope that it will be useful, |
| 16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 18 | * Lesser General Public License for more details. |
| 19 | * |
| 20 | * You should have received a copy of the GNU Lesser General Public |
| 21 | * License along with FFmpeg; if not, write to the Free Software |
| 22 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 23 | */ |
| 24 | |
| 25 | #include "avcodec.h" |
| 26 | #include "get_bits.h" |
| 27 | #include "internal.h" |
| 28 | |
| 29 | |
| 30 | #define FRAME_HEADER_SIZE 64 |
| 31 | #define MAGIC_0 0x19 /**< First header byte */ |
| 32 | #define MAGIC_1 0x68 /**< Second header byte */ |
| 33 | #define SUBSAMPLE_420 0 |
| 34 | #define SUBSAMPLE_422 1 |
| 35 | #define YUVORDER_YUYV 0 |
| 36 | #define YUVORDER_UYVY 1 |
| 37 | #define NOT_COMPRESSED 0 |
| 38 | #define COMPRESSED 1 |
| 39 | #define NO_DECIMATION 0 |
| 40 | #define DECIMATION_ENAB 1 |
| 41 | #define EOL 0xfd /**< End Of Line marker */ |
| 42 | #define EOI 0xff /**< End Of Image marker */ |
| 43 | |
| 44 | |
| 45 | typedef struct { |
| 46 | AVFrame *frame; |
| 47 | } CpiaContext; |
| 48 | |
| 49 | |
| 50 | static int cpia_decode_frame(AVCodecContext *avctx, |
| 51 | void *data, int *got_frame, AVPacket* avpkt) |
| 52 | { |
| 53 | CpiaContext* const cpia = avctx->priv_data; |
| 54 | int i,j,ret; |
| 55 | |
| 56 | uint8_t* const header = avpkt->data; |
| 57 | uint8_t* src; |
| 58 | int src_size; |
| 59 | uint16_t linelength; |
| 60 | uint8_t skip; |
| 61 | |
| 62 | AVFrame *frame = cpia->frame; |
| 63 | uint8_t *y, *u, *v, *y_end, *u_end, *v_end; |
| 64 | |
| 65 | // Check header |
| 66 | if ( avpkt->size < FRAME_HEADER_SIZE |
| 67 | || header[0] != MAGIC_0 || header[1] != MAGIC_1 |
| 68 | || (header[17] != SUBSAMPLE_420 && header[17] != SUBSAMPLE_422) |
| 69 | || (header[18] != YUVORDER_YUYV && header[18] != YUVORDER_UYVY) |
| 70 | || (header[28] != NOT_COMPRESSED && header[28] != COMPRESSED) |
| 71 | || (header[29] != NO_DECIMATION && header[29] != DECIMATION_ENAB) |
| 72 | ) { |
| 73 | av_log(avctx, AV_LOG_ERROR, "Invalid header!\n"); |
| 74 | return AVERROR_INVALIDDATA; |
| 75 | } |
| 76 | |
| 77 | // currently unsupported properties |
| 78 | if (header[17] == SUBSAMPLE_422) { |
| 79 | avpriv_report_missing_feature(avctx, "4:2:2 subsampling"); |
| 80 | return AVERROR_PATCHWELCOME; |
| 81 | } |
| 82 | if (header[18] == YUVORDER_UYVY) { |
| 83 | avpriv_report_missing_feature(avctx, "YUV byte order UYVY"); |
| 84 | return AVERROR_PATCHWELCOME; |
| 85 | } |
| 86 | if (header[29] == DECIMATION_ENAB) { |
| 87 | avpriv_report_missing_feature(avctx, "Decimation"); |
| 88 | return AVERROR_PATCHWELCOME; |
| 89 | } |
| 90 | |
| 91 | src = header + FRAME_HEADER_SIZE; |
| 92 | src_size = avpkt->size - FRAME_HEADER_SIZE; |
| 93 | |
| 94 | if (header[28] == NOT_COMPRESSED) { |
| 95 | frame->pict_type = AV_PICTURE_TYPE_I; |
| 96 | frame->key_frame = 1; |
| 97 | } else { |
| 98 | frame->pict_type = AV_PICTURE_TYPE_P; |
| 99 | frame->key_frame = 0; |
| 100 | } |
| 101 | |
| 102 | // Get buffer filled with previous frame |
| 103 | if ((ret = ff_reget_buffer(avctx, frame)) < 0) |
| 104 | return ret; |
| 105 | |
| 106 | |
| 107 | for ( i = 0; |
| 108 | i < frame->height; |
| 109 | i++, src += linelength, src_size -= linelength |
| 110 | ) { |
| 111 | // Read line length, two byte little endian |
| 112 | linelength = AV_RL16(src); |
| 113 | src += 2; |
| 114 | |
| 115 | if (src_size < linelength) { |
| 116 | av_frame_set_decode_error_flags(frame, FF_DECODE_ERROR_INVALID_BITSTREAM); |
| 117 | av_log(avctx, AV_LOG_WARNING, "Frame ended unexpectedly!\n"); |
| 118 | break; |
| 119 | } |
| 120 | if (src[linelength - 1] != EOL) { |
| 121 | av_frame_set_decode_error_flags(frame, FF_DECODE_ERROR_INVALID_BITSTREAM); |
| 122 | av_log(avctx, AV_LOG_WARNING, "Wrong line length %d or line not terminated properly (found 0x%02x)!\n", linelength, src[linelength - 1]); |
| 123 | break; |
| 124 | } |
| 125 | |
| 126 | /* Update the data pointers. Y data is on every line. |
| 127 | * U and V data on every second line |
| 128 | */ |
| 129 | y = &frame->data[0][i * frame->linesize[0]]; |
| 130 | u = &frame->data[1][(i >> 1) * frame->linesize[1]]; |
| 131 | v = &frame->data[2][(i >> 1) * frame->linesize[2]]; |
| 132 | y_end = y + frame->linesize[0] - 1; |
| 133 | u_end = u + frame->linesize[1] - 1; |
| 134 | v_end = v + frame->linesize[2] - 1; |
| 135 | |
| 136 | if ((i & 1) && header[17] == SUBSAMPLE_420) { |
| 137 | /* We are on a odd line and 420 subsample is used. |
| 138 | * On this line only Y values are specified, one per pixel. |
| 139 | */ |
| 140 | for (j = 0; j < linelength - 1; j++) { |
| 141 | if (y > y_end) { |
| 142 | av_frame_set_decode_error_flags(frame, FF_DECODE_ERROR_INVALID_BITSTREAM); |
| 143 | av_log(avctx, AV_LOG_WARNING, "Decoded data exceeded linesize!\n"); |
| 144 | break; |
| 145 | } |
| 146 | if ((src[j] & 1) && header[28] == COMPRESSED) { |
| 147 | /* It seems that odd lines are always uncompressed, but |
| 148 | * we do it according to specification anyways. |
| 149 | */ |
| 150 | skip = src[j] >> 1; |
| 151 | y += skip; |
| 152 | } else { |
| 153 | *(y++) = src[j]; |
| 154 | } |
| 155 | } |
| 156 | } else if (header[17] == SUBSAMPLE_420) { |
| 157 | /* We are on an even line and 420 subsample is used. |
| 158 | * On this line each pair of pixels is described by four bytes. |
| 159 | */ |
| 160 | for (j = 0; j < linelength - 4; ) { |
| 161 | if (y + 1 > y_end || u > u_end || v > v_end) { |
| 162 | av_frame_set_decode_error_flags(frame, FF_DECODE_ERROR_INVALID_BITSTREAM); |
| 163 | av_log(avctx, AV_LOG_WARNING, "Decoded data exceeded linesize!\n"); |
| 164 | break; |
| 165 | } |
| 166 | if ((src[j] & 1) && header[28] == COMPRESSED) { |
| 167 | // Skip amount of pixels and move forward one byte |
| 168 | skip = src[j] >> 1; |
| 169 | y += skip; |
| 170 | u += skip >> 1; |
| 171 | v += skip >> 1; |
| 172 | j++; |
| 173 | } else { |
| 174 | // Set image data as specified and move forward 4 bytes |
| 175 | *(y++) = src[j]; |
| 176 | *(u++) = src[j+1]; |
| 177 | *(y++) = src[j+2]; |
| 178 | *(v++) = src[j+3]; |
| 179 | j += 4; |
| 180 | } |
| 181 | } |
| 182 | } |
| 183 | } |
| 184 | |
| 185 | *got_frame = 1; |
| 186 | if ((ret = av_frame_ref(data, cpia->frame)) < 0) |
| 187 | return ret; |
| 188 | |
| 189 | return avpkt->size; |
| 190 | } |
| 191 | |
| 192 | static av_cold int cpia_decode_init(AVCodecContext *avctx) |
| 193 | { |
| 194 | CpiaContext *s = avctx->priv_data; |
| 195 | |
| 196 | // output pixel format |
| 197 | avctx->pix_fmt = AV_PIX_FMT_YUV420P; |
| 198 | |
| 199 | /* The default timebase set by the v4l2 demuxer leads to probing which is buggy. |
| 200 | * Set some reasonable time_base to skip this. |
| 201 | */ |
| 202 | if (avctx->time_base.num == 1 && avctx->time_base.den == 1000000) { |
| 203 | avctx->time_base.num = 1; |
| 204 | avctx->time_base.den = 60; |
| 205 | } |
| 206 | |
| 207 | s->frame = av_frame_alloc(); |
| 208 | if (!s->frame) |
| 209 | return AVERROR(ENOMEM); |
| 210 | |
| 211 | return 0; |
| 212 | } |
| 213 | |
| 214 | static av_cold int cpia_decode_end(AVCodecContext *avctx) |
| 215 | { |
| 216 | CpiaContext *s = avctx->priv_data; |
| 217 | |
| 218 | av_frame_free(&s->frame); |
| 219 | |
| 220 | return 0; |
| 221 | } |
| 222 | |
| 223 | AVCodec ff_cpia_decoder = { |
| 224 | .name = "cpia", |
| 225 | .long_name = NULL_IF_CONFIG_SMALL("CPiA video format"), |
| 226 | .type = AVMEDIA_TYPE_VIDEO, |
| 227 | .id = AV_CODEC_ID_CPIA, |
| 228 | .priv_data_size = sizeof(CpiaContext), |
| 229 | .init = cpia_decode_init, |
| 230 | .close = cpia_decode_end, |
| 231 | .decode = cpia_decode_frame, |
| 232 | .capabilities = CODEC_CAP_DR1, |
| 233 | }; |