1/*
2 * Quicktime Video (RPZA) Video Decoder
3 * Copyright (C) 2003 the ffmpeg project
4 *
5 * This file is part of FFmpeg.
6 *
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.
11 *
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.
16 *
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
20 */
21
22/**
23 * @file libavcodec/rpza.c
24 * QT RPZA Video Decoder by Roberto Togni
25 * For more information about the RPZA format, visit:
26 *   http://www.pcisys.net/~melanson/codecs/
27 *
28 * The RPZA decoder outputs RGB555 colorspace data.
29 *
30 * Note that this decoder reads big endian RGB555 pixel values from the
31 * bytestream, arranges them in the host's endian order, and outputs
32 * them to the final rendered map in the same host endian order. This is
33 * intended behavior as the ffmpeg documentation states that RGB555 pixels
34 * shall be stored in native CPU endianness.
35 */
36
37#include <stdio.h>
38#include <stdlib.h>
39#include <string.h>
40#include <unistd.h>
41
42#include "libavutil/intreadwrite.h"
43#include "avcodec.h"
44
45typedef struct RpzaContext {
46
47    AVCodecContext *avctx;
48    AVFrame frame;
49
50    const unsigned char *buf;
51    int size;
52
53} RpzaContext;
54
55#define ADVANCE_BLOCK() \
56{ \
57    pixel_ptr += 4; \
58    if (pixel_ptr >= width) \
59    { \
60        pixel_ptr = 0; \
61        row_ptr += stride * 4; \
62    } \
63    total_blocks--; \
64    if (total_blocks < 0) \
65    { \
66        av_log(s->avctx, AV_LOG_ERROR, "warning: block counter just went negative (this should not happen)\n"); \
67        return; \
68    } \
69}
70
71static void rpza_decode_stream(RpzaContext *s)
72{
73    int width = s->avctx->width;
74    int stride = s->frame.linesize[0] / 2;
75    int row_inc = stride - 4;
76    int stream_ptr = 0;
77    int chunk_size;
78    unsigned char opcode;
79    int n_blocks;
80    unsigned short colorA = 0, colorB;
81    unsigned short color4[4];
82    unsigned char index, idx;
83    unsigned short ta, tb;
84    unsigned short *pixels = (unsigned short *)s->frame.data[0];
85
86    int row_ptr = 0;
87    int pixel_ptr = 0;
88    int block_ptr;
89    int pixel_x, pixel_y;
90    int total_blocks;
91
92    /* First byte is always 0xe1. Warn if it's different */
93    if (s->buf[stream_ptr] != 0xe1)
94        av_log(s->avctx, AV_LOG_ERROR, "First chunk byte is 0x%02x instead of 0xe1\n",
95            s->buf[stream_ptr]);
96
97    /* Get chunk size, ingnoring first byte */
98    chunk_size = AV_RB32(&s->buf[stream_ptr]) & 0x00FFFFFF;
99    stream_ptr += 4;
100
101    /* If length mismatch use size from MOV file and try to decode anyway */
102    if (chunk_size != s->size)
103        av_log(s->avctx, AV_LOG_ERROR, "MOV chunk size != encoded chunk size; using MOV chunk size\n");
104
105    chunk_size = s->size;
106
107    /* Number of 4x4 blocks in frame. */
108    total_blocks = ((s->avctx->width + 3) / 4) * ((s->avctx->height + 3) / 4);
109
110    /* Process chunk data */
111    while (stream_ptr < chunk_size) {
112        opcode = s->buf[stream_ptr++]; /* Get opcode */
113
114        n_blocks = (opcode & 0x1f) + 1; /* Extract block counter from opcode */
115
116        /* If opcode MSbit is 0, we need more data to decide what to do */
117        if ((opcode & 0x80) == 0) {
118            colorA = (opcode << 8) | (s->buf[stream_ptr++]);
119            opcode = 0;
120            if ((s->buf[stream_ptr] & 0x80) != 0) {
121                /* Must behave as opcode 110xxxxx, using colorA computed
122                 * above. Use fake opcode 0x20 to enter switch block at
123                 * the right place */
124                opcode = 0x20;
125                n_blocks = 1;
126            }
127        }
128
129        switch (opcode & 0xe0) {
130
131        /* Skip blocks */
132        case 0x80:
133            while (n_blocks--) {
134              ADVANCE_BLOCK();
135            }
136            break;
137
138        /* Fill blocks with one color */
139        case 0xa0:
140            colorA = AV_RB16 (&s->buf[stream_ptr]);
141            stream_ptr += 2;
142            while (n_blocks--) {
143                block_ptr = row_ptr + pixel_ptr;
144                for (pixel_y = 0; pixel_y < 4; pixel_y++) {
145                    for (pixel_x = 0; pixel_x < 4; pixel_x++){
146                        pixels[block_ptr] = colorA;
147                        block_ptr++;
148                    }
149                    block_ptr += row_inc;
150                }
151                ADVANCE_BLOCK();
152            }
153            break;
154
155        /* Fill blocks with 4 colors */
156        case 0xc0:
157            colorA = AV_RB16 (&s->buf[stream_ptr]);
158            stream_ptr += 2;
159        case 0x20:
160            colorB = AV_RB16 (&s->buf[stream_ptr]);
161            stream_ptr += 2;
162
163            /* sort out the colors */
164            color4[0] = colorB;
165            color4[1] = 0;
166            color4[2] = 0;
167            color4[3] = colorA;
168
169            /* red components */
170            ta = (colorA >> 10) & 0x1F;
171            tb = (colorB >> 10) & 0x1F;
172            color4[1] |= ((11 * ta + 21 * tb) >> 5) << 10;
173            color4[2] |= ((21 * ta + 11 * tb) >> 5) << 10;
174
175            /* green components */
176            ta = (colorA >> 5) & 0x1F;
177            tb = (colorB >> 5) & 0x1F;
178            color4[1] |= ((11 * ta + 21 * tb) >> 5) << 5;
179            color4[2] |= ((21 * ta + 11 * tb) >> 5) << 5;
180
181            /* blue components */
182            ta = colorA & 0x1F;
183            tb = colorB & 0x1F;
184            color4[1] |= ((11 * ta + 21 * tb) >> 5);
185            color4[2] |= ((21 * ta + 11 * tb) >> 5);
186
187            while (n_blocks--) {
188                block_ptr = row_ptr + pixel_ptr;
189                for (pixel_y = 0; pixel_y < 4; pixel_y++) {
190                    index = s->buf[stream_ptr++];
191                    for (pixel_x = 0; pixel_x < 4; pixel_x++){
192                        idx = (index >> (2 * (3 - pixel_x))) & 0x03;
193                        pixels[block_ptr] = color4[idx];
194                        block_ptr++;
195                    }
196                    block_ptr += row_inc;
197                }
198                ADVANCE_BLOCK();
199            }
200            break;
201
202        /* Fill block with 16 colors */
203        case 0x00:
204            block_ptr = row_ptr + pixel_ptr;
205            for (pixel_y = 0; pixel_y < 4; pixel_y++) {
206                for (pixel_x = 0; pixel_x < 4; pixel_x++){
207                    /* We already have color of upper left pixel */
208                    if ((pixel_y != 0) || (pixel_x !=0)) {
209                        colorA = AV_RB16 (&s->buf[stream_ptr]);
210                        stream_ptr += 2;
211                    }
212                    pixels[block_ptr] = colorA;
213                    block_ptr++;
214                }
215                block_ptr += row_inc;
216            }
217            ADVANCE_BLOCK();
218            break;
219
220        /* Unknown opcode */
221        default:
222            av_log(s->avctx, AV_LOG_ERROR, "Unknown opcode %d in rpza chunk."
223                 " Skip remaining %d bytes of chunk data.\n", opcode,
224                 chunk_size - stream_ptr);
225            return;
226        } /* Opcode switch */
227    }
228}
229
230static av_cold int rpza_decode_init(AVCodecContext *avctx)
231{
232    RpzaContext *s = avctx->priv_data;
233
234    s->avctx = avctx;
235    avctx->pix_fmt = PIX_FMT_RGB555;
236
237    s->frame.data[0] = NULL;
238
239    return 0;
240}
241
242static int rpza_decode_frame(AVCodecContext *avctx,
243                             void *data, int *data_size,
244                             const uint8_t *buf, int buf_size)
245{
246    RpzaContext *s = avctx->priv_data;
247
248    s->buf = buf;
249    s->size = buf_size;
250
251    s->frame.reference = 1;
252    s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
253    if (avctx->reget_buffer(avctx, &s->frame)) {
254        av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
255        return -1;
256    }
257
258    rpza_decode_stream(s);
259
260    *data_size = sizeof(AVFrame);
261    *(AVFrame*)data = s->frame;
262
263    /* always report that the buffer was completely consumed */
264    return buf_size;
265}
266
267static av_cold int rpza_decode_end(AVCodecContext *avctx)
268{
269    RpzaContext *s = avctx->priv_data;
270
271    if (s->frame.data[0])
272        avctx->release_buffer(avctx, &s->frame);
273
274    return 0;
275}
276
277AVCodec rpza_decoder = {
278    "rpza",
279    CODEC_TYPE_VIDEO,
280    CODEC_ID_RPZA,
281    sizeof(RpzaContext),
282    rpza_decode_init,
283    NULL,
284    rpza_decode_end,
285    rpza_decode_frame,
286    CODEC_CAP_DR1,
287    .long_name = NULL_IF_CONFIG_SMALL("QuickTime video (RPZA)"),
288};
289