summaryrefslogtreecommitdiff
path: root/libavcodec/rpza.c
blob: ea90ed6756a56bc8b40574b2c198200f94d4462b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
/*
 * Quicktime Video (RPZA) Video Decoder
 * Copyright (C) 2003 the ffmpeg project
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file
 * QT RPZA Video Decoder by Roberto Togni
 * For more information about the RPZA format, visit:
 *   http://www.pcisys.net/~melanson/codecs/
 *
 * The RPZA decoder outputs RGB555 colorspace data.
 *
 * Note that this decoder reads big endian RGB555 pixel values from the
 * bytestream, arranges them in the host's endian order, and outputs
 * them to the final rendered map in the same host endian order. This is
 * intended behavior as the ffmpeg documentation states that RGB555 pixels
 * shall be stored in native CPU endianness.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "libavutil/intreadwrite.h"
#include "avcodec.h"

typedef struct RpzaContext {

    AVCodecContext *avctx;
    AVFrame frame;

    const unsigned char *buf;
    int size;

} RpzaContext;

#define ADVANCE_BLOCK() \
{ \
    pixel_ptr += 4; \
    if (pixel_ptr >= width) \
    { \
        pixel_ptr = 0; \
        row_ptr += stride * 4; \
    } \
    total_blocks--; \
    if (total_blocks < 0) \
    { \
        av_log(s->avctx, AV_LOG_ERROR, "warning: block counter just went negative (this should not happen)\n"); \
        return; \
    } \
}

static void rpza_decode_stream(RpzaContext *s)
{
    int width = s->avctx->width;
    int stride = s->frame.linesize[0] / 2;
    int row_inc = stride - 4;
    int stream_ptr = 0;
    int chunk_size;
    unsigned char opcode;
    int n_blocks;
    unsigned short colorA = 0, colorB;
    unsigned short color4[4];
    unsigned char index, idx;
    unsigned short ta, tb;
    unsigned short *pixels = (unsigned short *)s->frame.data[0];

    int row_ptr = 0;
    int pixel_ptr = 0;
    int block_ptr;
    int pixel_x, pixel_y;
    int total_blocks;

    /* First byte is always 0xe1. Warn if it's different */
    if (s->buf[stream_ptr] != 0xe1)
        av_log(s->avctx, AV_LOG_ERROR, "First chunk byte is 0x%02x instead of 0xe1\n",
            s->buf[stream_ptr]);

    /* Get chunk size, ingnoring first byte */
    chunk_size = AV_RB32(&s->buf[stream_ptr]) & 0x00FFFFFF;
    stream_ptr += 4;

    /* If length mismatch use size from MOV file and try to decode anyway */
    if (chunk_size != s->size)
        av_log(s->avctx, AV_LOG_ERROR, "MOV chunk size != encoded chunk size; using MOV chunk size\n");

    chunk_size = s->size;

    /* Number of 4x4 blocks in frame. */
    total_blocks = ((s->avctx->width + 3) / 4) * ((s->avctx->height + 3) / 4);

    /* Process chunk data */
    while (stream_ptr < chunk_size) {
        opcode = s->buf[stream_ptr++]; /* Get opcode */

        n_blocks = (opcode & 0x1f) + 1; /* Extract block counter from opcode */

        /* If opcode MSbit is 0, we need more data to decide what to do */
        if ((opcode & 0x80) == 0) {
            colorA = (opcode << 8) | (s->buf[stream_ptr++]);
            opcode = 0;
            if ((s->buf[stream_ptr] & 0x80) != 0) {
                /* Must behave as opcode 110xxxxx, using colorA computed
                 * above. Use fake opcode 0x20 to enter switch block at
                 * the right place */
                opcode = 0x20;
                n_blocks = 1;
            }
        }

        switch (opcode & 0xe0) {

        /* Skip blocks */
        case 0x80:
            while (n_blocks--) {
              ADVANCE_BLOCK();
            }
            break;

        /* Fill blocks with one color */
        case 0xa0:
            colorA = AV_RB16 (&s->buf[stream_ptr]);
            stream_ptr += 2;
            while (n_blocks--) {
                block_ptr = row_ptr + pixel_ptr;
                for (pixel_y = 0; pixel_y < 4; pixel_y++) {
                    for (pixel_x = 0; pixel_x < 4; pixel_x++){
                        pixels[block_ptr] = colorA;
                        block_ptr++;
                    }
                    block_ptr += row_inc;
                }
                ADVANCE_BLOCK();
            }
            break;

        /* Fill blocks with 4 colors */
        case 0xc0:
            colorA = AV_RB16 (&s->buf[stream_ptr]);
            stream_ptr += 2;
        case 0x20:
            colorB = AV_RB16 (&s->buf[stream_ptr]);
            stream_ptr += 2;

            /* sort out the colors */
            color4[0] = colorB;
            color4[1] = 0;
            color4[2] = 0;
            color4[3] = colorA;

            /* red components */
            ta = (colorA >> 10) & 0x1F;
            tb = (colorB >> 10) & 0x1F;
            color4[1] |= ((11 * ta + 21 * tb) >> 5) << 10;
            color4[2] |= ((21 * ta + 11 * tb) >> 5) << 10;

            /* green components */
            ta = (colorA >> 5) & 0x1F;
            tb = (colorB >> 5) & 0x1F;
            color4[1] |= ((11 * ta + 21 * tb) >> 5) << 5;
            color4[2] |= ((21 * ta + 11 * tb) >> 5) << 5;

            /* blue components */
            ta = colorA & 0x1F;
            tb = colorB & 0x1F;
            color4[1] |= ((11 * ta + 21 * tb) >> 5);
            color4[2] |= ((21 * ta + 11 * tb) >> 5);

            while (n_blocks--) {
                block_ptr = row_ptr + pixel_ptr;
                for (pixel_y = 0; pixel_y < 4; pixel_y++) {
                    index = s->buf[stream_ptr++];
                    for (pixel_x = 0; pixel_x < 4; pixel_x++){
                        idx = (index >> (2 * (3 - pixel_x))) & 0x03;
                        pixels[block_ptr] = color4[idx];
                        block_ptr++;
                    }
                    block_ptr += row_inc;
                }
                ADVANCE_BLOCK();
            }
            break;

        /* Fill block with 16 colors */
        case 0x00:
            block_ptr = row_ptr + pixel_ptr;
            for (pixel_y = 0; pixel_y < 4; pixel_y++) {
                for (pixel_x = 0; pixel_x < 4; pixel_x++){
                    /* We already have color of upper left pixel */
                    if ((pixel_y != 0) || (pixel_x !=0)) {
                        colorA = AV_RB16 (&s->buf[stream_ptr]);
                        stream_ptr += 2;
                    }
                    pixels[block_ptr] = colorA;
                    block_ptr++;
                }
                block_ptr += row_inc;
            }
            ADVANCE_BLOCK();
            break;

        /* Unknown opcode */
        default:
            av_log(s->avctx, AV_LOG_ERROR, "Unknown opcode %d in rpza chunk."
                 " Skip remaining %d bytes of chunk data.\n", opcode,
                 chunk_size - stream_ptr);
            return;
        } /* Opcode switch */
    }
}

static av_cold int rpza_decode_init(AVCodecContext *avctx)
{
    RpzaContext *s = avctx->priv_data;

    s->avctx = avctx;
    avctx->pix_fmt = PIX_FMT_RGB555;

    avcodec_get_frame_defaults(&s->frame);
    s->frame.data[0] = NULL;

    return 0;
}

static int rpza_decode_frame(AVCodecContext *avctx,
                             void *data, int *data_size,
                             AVPacket *avpkt)
{
    const uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size;
    RpzaContext *s = avctx->priv_data;

    s->buf = buf;
    s->size = buf_size;

    s->frame.reference = 1;
    s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
    if (avctx->reget_buffer(avctx, &s->frame)) {
        av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
        return -1;
    }

    rpza_decode_stream(s);

    *data_size = sizeof(AVFrame);
    *(AVFrame*)data = s->frame;

    /* always report that the buffer was completely consumed */
    return buf_size;
}

static av_cold int rpza_decode_end(AVCodecContext *avctx)
{
    RpzaContext *s = avctx->priv_data;

    if (s->frame.data[0])
        avctx->release_buffer(avctx, &s->frame);

    return 0;
}

AVCodec ff_rpza_decoder = {
    .name           = "rpza",
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = CODEC_ID_RPZA,
    .priv_data_size = sizeof(RpzaContext),
    .init           = rpza_decode_init,
    .close          = rpza_decode_end,
    .decode         = rpza_decode_frame,
    .capabilities   = CODEC_CAP_DR1,
    .long_name = NULL_IF_CONFIG_SMALL("QuickTime video (RPZA)"),
};