ffmpeg/libavcodec/8bps.c

   1 /*
   2  * Quicktime Planar RGB (8BPS) Video Decoder
   3  * Copyright (C) 2003 Roberto Togni
   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  * QT 8BPS Video Decoder by Roberto Togni
  25  * For more information about the 8BPS format, visit:
  26  *   http://www.pcisys.net/~melanson/codecs/
  27  *
  28  * Supports: PAL8 (RGB 8bpp, paletted)
  29  *         : BGR24 (RGB 24bpp) (can also output it as RGB32)
  30  *         : RGB32 (RGB 32bpp, 4th plane is alpha)
  31  *
  32  */
  33
  34 #include <stdio.h>
  35 #include <stdlib.h>
  36 #include <string.h>
  37
  38 #include "libavutil/internal.h"
  39 #include "libavutil/intreadwrite.h"
  40 #include "avcodec.h"
  41 #include "internal.h"
  42
  43
  44 static const enum AVPixelFormat pixfmt_rgb24[] = {
  45     AV_PIX_FMT_BGR24, AV_PIX_FMT_RGB32, AV_PIX_FMT_NONE };
  46
  47 typedef struct EightBpsContext {
  48     AVCodecContext *avctx;
  49
  50     unsigned char planes;
  51     unsigned char planemap[4];
  52
  53     uint32_t pal[256];
  54 } EightBpsContext;
  55
  56 static int decode_frame(AVCodecContext *avctx, void *data,
  57                         int *got_frame, AVPacket *avpkt)
  58 {
  59     AVFrame *frame = data;
  60     const uint8_t *buf = avpkt->data;
  61     int buf_size       = avpkt->size;
  62     EightBpsContext * const c = avctx->priv_data;
  63     const unsigned char *encoded = buf;
  64     unsigned char *pixptr, *pixptr_end;
  65     unsigned int height = avctx->height; // Real image height
  66     unsigned int dlen, p, row;
  67     const unsigned char *lp, *dp, *ep;
  68     unsigned char count;
  69     unsigned int planes     = c->planes;
  70     unsigned char *planemap = c->planemap;
  71     int ret;
  72
  73     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
  74         return ret;
  75
  76     ep = encoded + buf_size;
  77
  78     /* Set data pointer after line lengths */
  79     dp = encoded + planes * (height << 1);
  80
  81     for (p = 0; p < planes; p++) {
  82         /* Lines length pointer for this plane */
  83         lp = encoded + p * (height << 1);
  84
  85         /* Decode a plane */
  86         for (row = 0; row < height; row++) {
  87             pixptr = frame->data[0] + row * frame->linesize[0] + planemap[p];
  88             pixptr_end = pixptr + frame->linesize[0];
  89             if (ep - lp < row * 2 + 2)
  90                 return AVERROR_INVALIDDATA;
  91             dlen = av_be2ne16(*(const unsigned short *)(lp + row * 2));
  92             /* Decode a row of this plane */
  93             while (dlen > 0) {
  94                 if (ep - dp <= 1)
  95                     return AVERROR_INVALIDDATA;
  96                 if ((count = *dp++) <= 127) {
  97                     count++;
  98                     dlen -= count + 1;
  99                     if (pixptr_end - pixptr < count * planes)
 100                         break;
 101                     if (ep - dp < count)
 102                         return AVERROR_INVALIDDATA;
 103                     while (count--) {
 104                         *pixptr = *dp++;
 105                         pixptr += planes;
 106                     }
 107                 } else {
 108                     count = 257 - count;
 109                     if (pixptr_end - pixptr < count * planes)
 110                         break;
 111                     while (count--) {
 112                         *pixptr = *dp;
 113                         pixptr += planes;
 114                     }
 115                     dp++;
 116                     dlen -= 2;
 117                 }
 118             }
 119         }
 120     }
 121
 122     if (avctx->bits_per_coded_sample <= 8) {
 123         const uint8_t *pal = av_packet_get_side_data(avpkt,
 124                                                      AV_PKT_DATA_PALETTE,
 125                                                      NULL);
 126         if (pal) {
 127             frame->palette_has_changed = 1;
 128             memcpy(c->pal, pal, AVPALETTE_SIZE);
 129         }
 130
 131         memcpy (frame->data[1], c->pal, AVPALETTE_SIZE);
 132     }
 133
 134     *got_frame = 1;
 135
 136     /* always report that the buffer was completely consumed */
 137     return buf_size;
 138 }
 139
 140 static av_cold int decode_init(AVCodecContext *avctx)
 141 {
 142     EightBpsContext * const c = avctx->priv_data;
 143
 144     c->avctx       = avctx;
 145
 146     switch (avctx->bits_per_coded_sample) {
 147     case 8:
 148         avctx->pix_fmt = AV_PIX_FMT_PAL8;
 149         c->planes      = 1;
 150         c->planemap[0] = 0; // 1st plane is palette indexes
 151         break;
 152     case 24:
 153         avctx->pix_fmt = ff_get_format(avctx, pixfmt_rgb24);
 154         c->planes      = 3;
 155         c->planemap[0] = 2; // 1st plane is red
 156         c->planemap[1] = 1; // 2nd plane is green
 157         c->planemap[2] = 0; // 3rd plane is blue
 158         break;
 159     case 32:
 160         avctx->pix_fmt = AV_PIX_FMT_RGB32;
 161         c->planes      = 4;
 162         /* handle planemap setup later for decoding rgb24 data as rbg32 */
 163         break;
 164     default:
 165         av_log(avctx, AV_LOG_ERROR, "Error: Unsupported color depth: %u.\n",
 166                avctx->bits_per_coded_sample);
 167         return AVERROR_INVALIDDATA;
 168     }
 169
 170     if (avctx->pix_fmt == AV_PIX_FMT_RGB32) {
 171         c->planemap[0] = HAVE_BIGENDIAN ? 1 : 2; // 1st plane is red
 172         c->planemap[1] = HAVE_BIGENDIAN ? 2 : 1; // 2nd plane is green
 173         c->planemap[2] = HAVE_BIGENDIAN ? 3 : 0; // 3rd plane is blue
 174         c->planemap[3] = HAVE_BIGENDIAN ? 0 : 3; // 4th plane is alpha
 175     }
 176     return 0;
 177 }
 178
 179 AVCodec ff_eightbps_decoder = {
 180     .name           = "8bps",
 181     .long_name      = NULL_IF_CONFIG_SMALL("QuickTime 8BPS video"),
 182     .type           = AVMEDIA_TYPE_VIDEO,
 183     .id             = AV_CODEC_ID_8BPS,
 184     .priv_data_size = sizeof(EightBpsContext),
 185     .init           = decode_init,
 186     .decode         = decode_frame,
 187     .capabilities   = CODEC_CAP_DR1,
 188 };