3 * Copyright (C) 2008 Sascha Sommer (saschasommer@freenet.de)
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
25 * @author Sascha Sommer (saschasommer@freenet.de)
26 * @see http://wiki.multimedia.cx/index.php?title=RL2
33 #include "libavutil/internal.h"
34 #include "libavutil/intreadwrite.h"
35 #include "libavutil/mem.h"
40 #define EXTRADATA1_SIZE (6 + 256 * 3) ///< video base, clr count, palette
42 typedef struct Rl2Context
{
43 AVCodecContext
*avctx
;
45 uint16_t video_base
; ///< initial drawing offset
46 uint32_t clr_count
; ///< number of used colors (currently unused)
47 uint8_t *back_frame
; ///< background frame
48 uint32_t palette
[AVPALETTE_COUNT
];
52 * Run Length Decode a single 320x200 frame
53 * @param s rl2 context
54 * @param in input buffer
55 * @param size input buffer size
56 * @param out output buffer
57 * @param stride stride of the output buffer
58 * @param video_base offset of the rle data inside the frame
60 static void rl2_rle_decode(Rl2Context
*s
, const uint8_t *in
, int size
,
61 uint8_t *out
, int stride
, int video_base
)
63 int base_x
= video_base
% s
->avctx
->width
;
64 int base_y
= video_base
/ s
->avctx
->width
;
65 int stride_adj
= stride
- s
->avctx
->width
;
67 const uint8_t *back_frame
= s
->back_frame
;
68 const uint8_t *in_end
= in
+ size
;
69 const uint8_t *out_end
= out
+ stride
* s
->avctx
->height
;
72 /** copy start of the background frame */
73 for (i
= 0; i
<= base_y
; i
++) {
75 memcpy(out
, back_frame
, s
->avctx
->width
);
77 back_frame
+= s
->avctx
->width
;
79 back_frame
+= base_x
- s
->avctx
->width
;
80 line_end
= out
- stride_adj
;
81 out
+= base_x
- stride
;
83 /** decode the variable part of the frame */
95 if (len
>= out_end
- out
)
104 *out
++ = (val
== 0x80) ? *back_frame
: val
;
106 if (out
== line_end
) {
109 if (len
>= out_end
- out
)
115 /** copy the rest from the background frame */
117 while (out
< out_end
) {
118 memcpy(out
, back_frame
, line_end
- out
);
119 back_frame
+= line_end
- out
;
120 out
= line_end
+ stride_adj
;
128 * Initialize the decoder
129 * @param avctx decoder context
130 * @return 0 success, -1 on error
132 static av_cold
int rl2_decode_init(AVCodecContext
*avctx
)
134 Rl2Context
*s
= avctx
->priv_data
;
139 avctx
->pix_fmt
= AV_PIX_FMT_PAL8
;
141 /** parse extra data */
142 if (!avctx
->extradata
|| avctx
->extradata_size
< EXTRADATA1_SIZE
) {
143 av_log(avctx
, AV_LOG_ERROR
, "invalid extradata size\n");
144 return AVERROR(EINVAL
);
147 /** get frame_offset */
148 s
->video_base
= AV_RL16(&avctx
->extradata
[0]);
149 s
->clr_count
= AV_RL32(&avctx
->extradata
[2]);
151 if (s
->video_base
>= avctx
->width
* avctx
->height
) {
152 av_log(avctx
, AV_LOG_ERROR
, "invalid video_base\n");
153 return AVERROR_INVALIDDATA
;
156 /** initialize palette */
157 for (i
= 0; i
< AVPALETTE_COUNT
; i
++)
158 s
->palette
[i
] = 0xFFU
<< 24 | AV_RB24(&avctx
->extradata
[6 + i
* 3]);
160 /** decode background frame if present */
161 back_size
= avctx
->extradata_size
- EXTRADATA1_SIZE
;
164 uint8_t *back_frame
= av_mallocz(avctx
->width
*avctx
->height
);
166 return AVERROR(ENOMEM
);
167 rl2_rle_decode(s
, avctx
->extradata
+ EXTRADATA1_SIZE
, back_size
,
168 back_frame
, avctx
->width
, 0);
169 s
->back_frame
= back_frame
;
175 static int rl2_decode_frame(AVCodecContext
*avctx
,
176 void *data
, int *got_frame
,
179 AVFrame
*frame
= data
;
180 const uint8_t *buf
= avpkt
->data
;
181 int ret
, buf_size
= avpkt
->size
;
182 Rl2Context
*s
= avctx
->priv_data
;
184 if ((ret
= ff_get_buffer(avctx
, frame
, 0)) < 0)
187 /** run length decode */
188 rl2_rle_decode(s
, buf
, buf_size
, frame
->data
[0], frame
->linesize
[0],
191 /** make the palette available on the way out */
192 memcpy(frame
->data
[1], s
->palette
, AVPALETTE_SIZE
);
196 /** report that the buffer was completely consumed */
203 * @param avctx decoder context
204 * @return 0 success, -1 on error
206 static av_cold
int rl2_decode_end(AVCodecContext
*avctx
)
208 Rl2Context
*s
= avctx
->priv_data
;
210 av_freep(&s
->back_frame
);
216 AVCodec ff_rl2_decoder
= {
218 .long_name
= NULL_IF_CONFIG_SMALL("RL2 video"),
219 .type
= AVMEDIA_TYPE_VIDEO
,
220 .id
= AV_CODEC_ID_RL2
,
221 .priv_data_size
= sizeof(Rl2Context
),
222 .init
= rl2_decode_init
,
223 .close
= rl2_decode_end
,
224 .decode
= rl2_decode_frame
,
225 .capabilities
= CODEC_CAP_DR1
,