2 * Microsoft RLE video decoder
3 * Copyright (C) 2003 the ffmpeg project
5 * This file is part of FFmpeg.
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.
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.
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
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/
28 * The MS RLE decoder outputs PAL8 colorspace data.
39 typedef struct MsrleContext {
40 AVCodecContext *avctx;
44 const unsigned char *buf;
50 static av_cold int msrle_decode_init(AVCodecContext *avctx)
52 MsrleContext *s = avctx->priv_data;
57 switch (avctx->bits_per_coded_sample) {
59 avctx->pix_fmt = AV_PIX_FMT_MONOWHITE;
63 avctx->pix_fmt = AV_PIX_FMT_PAL8;
66 avctx->pix_fmt = AV_PIX_FMT_BGR24;
69 av_log(avctx, AV_LOG_ERROR, "unsupported bits per sample\n");
70 return AVERROR_INVALIDDATA;
73 avcodec_get_frame_defaults(&s->frame);
75 if (avctx->extradata_size >= 4)
76 for (i = 0; i < FFMIN(avctx->extradata_size, AVPALETTE_SIZE)/4; i++)
77 s->pal[i] = 0xFFU<<24 | AV_RL32(avctx->extradata+4*i);
82 static int msrle_decode_frame(AVCodecContext *avctx,
83 void *data, int *got_frame,
86 const uint8_t *buf = avpkt->data;
87 int buf_size = avpkt->size;
88 MsrleContext *s = avctx->priv_data;
89 int istride = FFALIGN(avctx->width*avctx->bits_per_coded_sample, 32) / 8;
95 if ((ret = ff_reget_buffer(avctx, &s->frame)) < 0)
98 if (avctx->bits_per_coded_sample > 1 && avctx->bits_per_coded_sample <= 8) {
99 const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
102 s->frame.palette_has_changed = 1;
103 memcpy(s->pal, pal, AVPALETTE_SIZE);
105 /* make the palette available */
106 memcpy(s->frame.data[1], s->pal, AVPALETTE_SIZE);
109 /* FIXME how to correctly detect RLE ??? */
110 if (avctx->height * istride == avpkt->size) { /* assume uncompressed */
111 int linesize = (avctx->width * avctx->bits_per_coded_sample + 7) / 8;
112 uint8_t *ptr = s->frame.data[0];
113 uint8_t *buf = avpkt->data + (avctx->height-1)*istride;
116 for (i = 0; i < avctx->height; i++) {
117 if (avctx->bits_per_coded_sample == 4) {
118 for (j = 0; j < avctx->width - 1; j += 2) {
119 ptr[j+0] = buf[j>>1] >> 4;
120 ptr[j+1] = buf[j>>1] & 0xF;
122 if (avctx->width & 1)
123 ptr[j+0] = buf[j>>1] >> 4;
125 memcpy(ptr, buf, linesize);
128 ptr += s->frame.linesize[0];
131 bytestream2_init(&s->gb, buf, buf_size);
132 ff_msrle_decode(avctx, (AVPicture*)&s->frame, avctx->bits_per_coded_sample, &s->gb);
135 if ((ret = av_frame_ref(data, &s->frame)) < 0)
140 /* report that the buffer was completely consumed */
144 static av_cold int msrle_decode_end(AVCodecContext *avctx)
146 MsrleContext *s = avctx->priv_data;
148 /* release the last frame */
149 av_frame_unref(&s->frame);
154 AVCodec ff_msrle_decoder = {
156 .type = AVMEDIA_TYPE_VIDEO,
157 .id = AV_CODEC_ID_MSRLE,
158 .priv_data_size = sizeof(MsrleContext),
159 .init = msrle_decode_init,
160 .close = msrle_decode_end,
161 .decode = msrle_decode_frame,
162 .capabilities = CODEC_CAP_DR1,
163 .long_name = NULL_IF_CONFIG_SMALL("Microsoft RLE"),