lavc: fix decode_frame() third parameter semantics for video decoders
[libav.git] / libavcodec / msrle.c
1 /*
2 * Microsoft RLE video decoder
3 * Copyright (C) 2003 the ffmpeg project
4 *
5 * This file is part of Libav.
6 *
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.
11 *
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.
16 *
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
20 */
21
22 /**
23 * @file
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
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34
35 #include "avcodec.h"
36 #include "dsputil.h"
37 #include "msrledec.h"
38
39 typedef struct MsrleContext {
40 AVCodecContext *avctx;
41 AVFrame frame;
42
43 GetByteContext gb;
44 const unsigned char *buf;
45 int size;
46
47 uint32_t pal[256];
48 } MsrleContext;
49
50 static av_cold int msrle_decode_init(AVCodecContext *avctx)
51 {
52 MsrleContext *s = avctx->priv_data;
53
54 s->avctx = avctx;
55
56 switch (avctx->bits_per_coded_sample) {
57 case 4:
58 case 8:
59 avctx->pix_fmt = AV_PIX_FMT_PAL8;
60 break;
61 case 24:
62 avctx->pix_fmt = AV_PIX_FMT_BGR24;
63 break;
64 default:
65 av_log(avctx, AV_LOG_ERROR, "unsupported bits per sample\n");
66 return -1;
67 }
68
69 s->frame.data[0] = NULL;
70
71 return 0;
72 }
73
74 static int msrle_decode_frame(AVCodecContext *avctx,
75 void *data, int *got_frame,
76 AVPacket *avpkt)
77 {
78 const uint8_t *buf = avpkt->data;
79 int buf_size = avpkt->size;
80 MsrleContext *s = avctx->priv_data;
81 int istride = FFALIGN(avctx->width*avctx->bits_per_coded_sample, 32) / 8;
82
83 s->buf = buf;
84 s->size = buf_size;
85
86 s->frame.reference = 1;
87 s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
88 if (avctx->reget_buffer(avctx, &s->frame)) {
89 av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
90 return -1;
91 }
92
93 if (avctx->bits_per_coded_sample <= 8) {
94 const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
95
96 if (pal) {
97 s->frame.palette_has_changed = 1;
98 memcpy(s->pal, pal, AVPALETTE_SIZE);
99 }
100
101 /* make the palette available */
102 memcpy(s->frame.data[1], s->pal, AVPALETTE_SIZE);
103 }
104
105 /* FIXME how to correctly detect RLE ??? */
106 if (avctx->height * istride == avpkt->size) { /* assume uncompressed */
107 int linesize = avctx->width * avctx->bits_per_coded_sample / 8;
108 uint8_t *ptr = s->frame.data[0];
109 uint8_t *buf = avpkt->data + (avctx->height-1)*istride;
110 int i, j;
111
112 for (i = 0; i < avctx->height; i++) {
113 if (avctx->bits_per_coded_sample == 4) {
114 for (j = 0; j < avctx->width - 1; j += 2) {
115 ptr[j+0] = buf[j>>1] >> 4;
116 ptr[j+1] = buf[j>>1] & 0xF;
117 }
118 if (avctx->width & 1)
119 ptr[j+0] = buf[j>>1] >> 4;
120 } else {
121 memcpy(ptr, buf, linesize);
122 }
123 buf -= istride;
124 ptr += s->frame.linesize[0];
125 }
126 } else {
127 bytestream2_init(&s->gb, buf, buf_size);
128 ff_msrle_decode(avctx, (AVPicture*)&s->frame, avctx->bits_per_coded_sample, &s->gb);
129 }
130
131 *got_frame = 1;
132 *(AVFrame*)data = s->frame;
133
134 /* report that the buffer was completely consumed */
135 return buf_size;
136 }
137
138 static av_cold int msrle_decode_end(AVCodecContext *avctx)
139 {
140 MsrleContext *s = avctx->priv_data;
141
142 /* release the last frame */
143 if (s->frame.data[0])
144 avctx->release_buffer(avctx, &s->frame);
145
146 return 0;
147 }
148
149 AVCodec ff_msrle_decoder = {
150 .name = "msrle",
151 .type = AVMEDIA_TYPE_VIDEO,
152 .id = AV_CODEC_ID_MSRLE,
153 .priv_data_size = sizeof(MsrleContext),
154 .init = msrle_decode_init,
155 .close = msrle_decode_end,
156 .decode = msrle_decode_frame,
157 .capabilities = CODEC_CAP_DR1,
158 .long_name = NULL_IF_CONFIG_SMALL("Microsoft RLE"),
159 };