libavcodec/msrle.c

   1 /*
   2  * Micrsoft RLE Video Decoder
   3  * Copyright (C) 2003 the ffmpeg project
   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 libavcodec/msrle.c
  24  * MS RLE Video Decoder by Mike Melanson (melanson@pcisys.net)
  25  * For more information about the MS RLE format, visit:
  26  *   http://www.pcisys.net/~melanson/codecs/
  27  *
  28  * The MS RLE decoder outputs PAL8 colorspace data.
  29  *
  30  * Note that this decoder expects the palette colors from the end of the
  31  * BITMAPINFO header passed through palctrl.
  32  */
  33
  34 #include <stdio.h>
  35 #include <stdlib.h>
  36 #include <string.h>
  37 #include <unistd.h>
  38
  39 #include "avcodec.h"
  40 #include "dsputil.h"
  41 #include "msrledec.h"
  42
  43 typedef struct MsrleContext {
  44     AVCodecContext *avctx;
  45     AVFrame frame;
  46
  47     const unsigned char *buf;
  48     int size;
  49
  50 } MsrleContext;
  51
  52 static av_cold int msrle_decode_init(AVCodecContext *avctx)
  53 {
  54     MsrleContext *s = avctx->priv_data;
  55
  56     s->avctx = avctx;
  57
  58     avctx->pix_fmt = PIX_FMT_PAL8;
  59     s->frame.data[0] = NULL;
  60
  61     return 0;
  62 }
  63
  64 static int msrle_decode_frame(AVCodecContext *avctx,
  65                               void *data, int *data_size,
  66                               AVPacket *avpkt)
  67 {
  68     const uint8_t *buf = avpkt->data;
  69     int buf_size = avpkt->size;
  70     MsrleContext *s = avctx->priv_data;
  71
  72     s->buf = buf;
  73     s->size = buf_size;
  74
  75     s->frame.reference = 1;
  76     s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
  77     if (avctx->reget_buffer(avctx, &s->frame)) {
  78         av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
  79         return -1;
  80     }
  81
  82     /* make the palette available */
  83     memcpy(s->frame.data[1], s->avctx->palctrl->palette, AVPALETTE_SIZE);
  84     if (s->avctx->palctrl->palette_changed) {
  85         s->frame.palette_has_changed = 1;
  86         s->avctx->palctrl->palette_changed = 0;
  87     }
  88
  89     ff_msrle_decode(avctx, (AVPicture*)&s->frame, avctx->bits_per_coded_sample, buf, buf_size);
  90
  91     *data_size = sizeof(AVFrame);
  92     *(AVFrame*)data = s->frame;
  93
  94     /* report that the buffer was completely consumed */
  95     return buf_size;
  96 }
  97
  98 static av_cold int msrle_decode_end(AVCodecContext *avctx)
  99 {
 100     MsrleContext *s = avctx->priv_data;
 101
 102     /* release the last frame */
 103     if (s->frame.data[0])
 104         avctx->release_buffer(avctx, &s->frame);
 105
 106     return 0;
 107 }
 108
 109 AVCodec msrle_decoder = {
 110     "msrle",
 111     CODEC_TYPE_VIDEO,
 112     CODEC_ID_MSRLE,
 113     sizeof(MsrleContext),
 114     msrle_decode_init,
 115     NULL,
 116     msrle_decode_end,
 117     msrle_decode_frame,
 118     CODEC_CAP_DR1,
 119     .long_name= NULL_IF_CONFIG_SMALL("Microsoft RLE"),
 120 };