2 * Microsoft RLE video decoder
3 * Copyright (C) 2003 The FFmpeg project
5 * This file is part of Libav.
7 * Libav 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 * Libav 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 Libav; 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;
56 switch (avctx->bits_per_coded_sample) {
59 avctx->pix_fmt = AV_PIX_FMT_PAL8;
62 avctx->pix_fmt = AV_PIX_FMT_BGR24;
65 av_log(avctx, AV_LOG_ERROR, "unsupported bits per sample\n");
66 return AVERROR_INVALIDDATA;
69 s->frame = av_frame_alloc();
71 return AVERROR(ENOMEM);
76 static int msrle_decode_frame(AVCodecContext *avctx,
77 void *data, int *got_frame,
80 const uint8_t *buf = avpkt->data;
81 int buf_size = avpkt->size;
82 MsrleContext *s = avctx->priv_data;
83 int istride = FFALIGN(avctx->width*avctx->bits_per_coded_sample, 32) / 8;
89 if ((ret = ff_reget_buffer(avctx, s->frame)) < 0) {
90 av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
94 if (avctx->bits_per_coded_sample <= 8) {
95 const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
98 s->frame->palette_has_changed = 1;
99 memcpy(s->pal, pal, AVPALETTE_SIZE);
102 /* make the palette available */
103 memcpy(s->frame->data[1], s->pal, AVPALETTE_SIZE);
106 /* FIXME how to correctly detect RLE ??? */
107 if (avctx->height * istride == avpkt->size) { /* assume uncompressed */
108 int linesize = avctx->width * avctx->bits_per_coded_sample / 8;
109 uint8_t *ptr = s->frame->data[0];
110 uint8_t *buf = avpkt->data + (avctx->height-1)*istride;
113 for (i = 0; i < avctx->height; i++) {
114 if (avctx->bits_per_coded_sample == 4) {
115 for (j = 0; j < avctx->width - 1; j += 2) {
116 ptr[j+0] = buf[j>>1] >> 4;
117 ptr[j+1] = buf[j>>1] & 0xF;
119 if (avctx->width & 1)
120 ptr[j+0] = buf[j>>1] >> 4;
122 memcpy(ptr, buf, linesize);
125 ptr += s->frame->linesize[0];
128 bytestream2_init(&s->gb, buf, buf_size);
129 ff_msrle_decode(avctx, s->frame, avctx->bits_per_coded_sample, &s->gb);
132 if ((ret = av_frame_ref(data, s->frame)) < 0)
137 /* report that the buffer was completely consumed */
141 static av_cold int msrle_decode_end(AVCodecContext *avctx)
143 MsrleContext *s = avctx->priv_data;
145 /* release the last frame */
146 av_frame_free(&s->frame);
151 AVCodec ff_msrle_decoder = {
153 .long_name = NULL_IF_CONFIG_SMALL("Microsoft RLE"),
154 .type = AVMEDIA_TYPE_VIDEO,
155 .id = AV_CODEC_ID_MSRLE,
156 .priv_data_size = sizeof(MsrleContext),
157 .init = msrle_decode_init,
158 .close = msrle_decode_end,
159 .decode = msrle_decode_frame,
160 .capabilities = AV_CODEC_CAP_DR1,