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 & 0x1f) {
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 s->frame = av_frame_alloc();
75 return AVERROR(ENOMEM);
77 if (avctx->extradata_size >= 4)
78 for (i = 0; i < FFMIN(avctx->extradata_size, AVPALETTE_SIZE)/4; i++)
79 s->pal[i] = 0xFFU<<24 | AV_RL32(avctx->extradata+4*i);
84 static int msrle_decode_frame(AVCodecContext *avctx,
85 void *data, int *got_frame,
88 const uint8_t *buf = avpkt->data;
89 int buf_size = avpkt->size;
90 MsrleContext *s = avctx->priv_data;
91 int istride = FFALIGN(avctx->width*avctx->bits_per_coded_sample, 32) / 8;
97 if ((ret = ff_reget_buffer(avctx, s->frame)) < 0)
100 if (avctx->bits_per_coded_sample > 1 && avctx->bits_per_coded_sample <= 8) {
101 const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
104 s->frame->palette_has_changed = 1;
105 memcpy(s->pal, pal, AVPALETTE_SIZE);
107 /* make the palette available */
108 memcpy(s->frame->data[1], s->pal, AVPALETTE_SIZE);
111 /* FIXME how to correctly detect RLE ??? */
112 if (avctx->height * istride == avpkt->size) { /* assume uncompressed */
113 int linesize = (avctx->width * avctx->bits_per_coded_sample + 7) / 8;
114 uint8_t *ptr = s->frame->data[0];
115 uint8_t *buf = avpkt->data + (avctx->height-1)*istride;
118 for (i = 0; i < avctx->height; i++) {
119 if (avctx->bits_per_coded_sample == 4) {
120 for (j = 0; j < avctx->width - 1; j += 2) {
121 ptr[j+0] = buf[j>>1] >> 4;
122 ptr[j+1] = buf[j>>1] & 0xF;
124 if (avctx->width & 1)
125 ptr[j+0] = buf[j>>1] >> 4;
127 memcpy(ptr, buf, linesize);
130 ptr += s->frame->linesize[0];
133 bytestream2_init(&s->gb, buf, buf_size);
134 ff_msrle_decode(avctx, (AVPicture*)s->frame, avctx->bits_per_coded_sample, &s->gb);
137 if ((ret = av_frame_ref(data, s->frame)) < 0)
142 /* report that the buffer was completely consumed */
146 static av_cold int msrle_decode_end(AVCodecContext *avctx)
148 MsrleContext *s = avctx->priv_data;
150 /* release the last frame */
151 av_frame_free(&s->frame);
156 AVCodec ff_msrle_decoder = {
158 .long_name = NULL_IF_CONFIG_SMALL("Microsoft RLE"),
159 .type = AVMEDIA_TYPE_VIDEO,
160 .id = AV_CODEC_ID_MSRLE,
161 .priv_data_size = sizeof(MsrleContext),
162 .init = msrle_decode_init,
163 .close = msrle_decode_end,
164 .decode = msrle_decode_frame,
165 .capabilities = CODEC_CAP_DR1,