1/*
2 * Quicktime Video (RPZA) 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 * 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 libavcodec documentation states that RGB555
34 * pixels shall be stored in native CPU endianness.
35 */
36
37#include <stdio.h>
38#include <stdlib.h>
39#include <string.h>
40
41#include "libavutil/intreadwrite.h"
42#include "avcodec.h"
43
44typedef struct RpzaContext {
45
46    AVCodecContext *avctx;
47    AVFrame frame;
48
49    const unsigned char *buf;
50    int size;
51
52} RpzaContext;
53
54#define ADVANCE_BLOCK() \
55{ \
56    pixel_ptr += 4; \
57    if (pixel_ptr >= width) \
58    { \
59        pixel_ptr = 0; \
60        row_ptr += stride * 4; \
61    } \
62    total_blocks--; \
63    if (total_blocks < 0) \
64    { \
65        av_log(s->avctx, AV_LOG_ERROR, "warning: block counter just went negative (this should not happen)\n"); \
66        return; \
67    } \
68}
69
70static void rpza_decode_stream(RpzaContext *s)
71{
72    int width = s->avctx->width;
73    int stride = s->frame.linesize[0] / 2;
74    int row_inc = stride - 4;
75    int stream_ptr = 0;
76    int chunk_size;
77    unsigned char opcode;
78    int n_blocks;
79    unsigned short colorA = 0, colorB;
80    unsigned short color4[4];
81    unsigned char index, idx;
82    unsigned short ta, tb;
83    unsigned short *pixels = (unsigned short *)s->frame.data[0];
84
85    int row_ptr = 0;
86    int pixel_ptr = 0;
87    int block_ptr;
88    int pixel_x, pixel_y;
89    int total_blocks;
90
91    /* First byte is always 0xe1. Warn if it's different */
92    if (s->buf[stream_ptr] != 0xe1)
93        av_log(s->avctx, AV_LOG_ERROR, "First chunk byte is 0x%02x instead of 0xe1\n",
94            s->buf[stream_ptr]);
95
96    /* Get chunk size, ingnoring first byte */
97    chunk_size = AV_RB32(&s->buf[stream_ptr]) & 0x00FFFFFF;
98    stream_ptr += 4;
99
100    /* If length mismatch use size from MOV file and try to decode anyway */
101    if (chunk_size != s->size)
102        av_log(s->avctx, AV_LOG_ERROR, "MOV chunk size != encoded chunk size; using MOV chunk size\n");
103
104    chunk_size = s->size;
105
106    /* Number of 4x4 blocks in frame. */
107    total_blocks = ((s->avctx->width + 3) / 4) * ((s->avctx->height + 3) / 4);
108
109    /* Process chunk data */
110    while (stream_ptr < chunk_size) {
111        opcode = s->buf[stream_ptr++]; /* Get opcode */
112
113        n_blocks = (opcode & 0x1f) + 1; /* Extract block counter from opcode */
114
115        /* If opcode MSbit is 0, we need more data to decide what to do */
116        if ((opcode & 0x80) == 0) {
117            colorA = (opcode << 8) | (s->buf[stream_ptr++]);
118            opcode = 0;
119            if ((s->buf[stream_ptr] & 0x80) != 0) {
120                /* Must behave as opcode 110xxxxx, using colorA computed
121                 * above. Use fake opcode 0x20 to enter switch block at
122                 * the right place */
123                opcode = 0x20;
124                n_blocks = 1;
125            }
126        }
127
128        switch (opcode & 0xe0) {
129
130        /* Skip blocks */
131        case 0x80:
132            while (n_blocks--) {
133              ADVANCE_BLOCK();
134            }
135            break;
136
137        /* Fill blocks with one color */
138        case 0xa0:
139            colorA = AV_RB16 (&s->buf[stream_ptr]);
140            stream_ptr += 2;
141            while (n_blocks--) {
142                block_ptr = row_ptr + pixel_ptr;
143                for (pixel_y = 0; pixel_y < 4; pixel_y++) {
144                    for (pixel_x = 0; pixel_x < 4; pixel_x++){
145                        pixels[block_ptr] = colorA;
146                        block_ptr++;
147                    }
148                    block_ptr += row_inc;
149                }
150                ADVANCE_BLOCK();
151            }
152            break;
153
154        /* Fill blocks with 4 colors */
155        case 0xc0:
156            colorA = AV_RB16 (&s->buf[stream_ptr]);
157            stream_ptr += 2;
158        case 0x20:
159            colorB = AV_RB16 (&s->buf[stream_ptr]);
160            stream_ptr += 2;
161
162            /* sort out the colors */
163            color4[0] = colorB;
164            color4[1] = 0;
165            color4[2] = 0;
166            color4[3] = colorA;
167
168            /* red components */
169            ta = (colorA >> 10) & 0x1F;
170            tb = (colorB >> 10) & 0x1F;
171            color4[1] |= ((11 * ta + 21 * tb) >> 5) << 10;
172            color4[2] |= ((21 * ta + 11 * tb) >> 5) << 10;
173
174            /* green components */
175            ta = (colorA >> 5) & 0x1F;
176            tb = (colorB >> 5) & 0x1F;
177            color4[1] |= ((11 * ta + 21 * tb) >> 5) << 5;
178            color4[2] |= ((21 * ta + 11 * tb) >> 5) << 5;
179
180            /* blue components */
181            ta = colorA & 0x1F;
182            tb = colorB & 0x1F;
183            color4[1] |= ((11 * ta + 21 * tb) >> 5);
184            color4[2] |= ((21 * ta + 11 * tb) >> 5);
185
186            if (s->size - stream_ptr < n_blocks * 4)
187                return;
188            while (n_blocks--) {
189                block_ptr = row_ptr + pixel_ptr;
190                for (pixel_y = 0; pixel_y < 4; pixel_y++) {
191                    index = s->buf[stream_ptr++];
192                    for (pixel_x = 0; pixel_x < 4; pixel_x++){
193                        idx = (index >> (2 * (3 - pixel_x))) & 0x03;
194                        pixels[block_ptr] = color4[idx];
195                        block_ptr++;
196                    }
197                    block_ptr += row_inc;
198                }
199                ADVANCE_BLOCK();
200            }
201            break;
202
203        /* Fill block with 16 colors */
204        case 0x00:
205            if (s->size - stream_ptr < 16)
206                return;
207            block_ptr = row_ptr + pixel_ptr;
208            for (pixel_y = 0; pixel_y < 4; pixel_y++) {
209                for (pixel_x = 0; pixel_x < 4; pixel_x++){
210                    /* We already have color of upper left pixel */
211                    if ((pixel_y != 0) || (pixel_x !=0)) {
212                        colorA = AV_RB16 (&s->buf[stream_ptr]);
213                        stream_ptr += 2;
214                    }
215                    pixels[block_ptr] = colorA;
216                    block_ptr++;
217                }
218                block_ptr += row_inc;
219            }
220            ADVANCE_BLOCK();
221            break;
222
223        /* Unknown opcode */
224        default:
225            av_log(s->avctx, AV_LOG_ERROR, "Unknown opcode %d in rpza chunk."
226                 " Skip remaining %d bytes of chunk data.\n", opcode,
227                 chunk_size - stream_ptr);
228            return;
229        } /* Opcode switch */
230    }
231}
232
233static av_cold int rpza_decode_init(AVCodecContext *avctx)
234{
235    RpzaContext *s = avctx->priv_data;
236
237    s->avctx = avctx;
238    avctx->pix_fmt = PIX_FMT_RGB555;
239
240    s->frame.data[0] = NULL;
241
242    return 0;
243}
244
245static int rpza_decode_frame(AVCodecContext *avctx,
246                             void *data, int *data_size,
247                             AVPacket *avpkt)
248{
249    const uint8_t *buf = avpkt->data;
250    int buf_size = avpkt->size;
251    RpzaContext *s = avctx->priv_data;
252
253    s->buf = buf;
254    s->size = buf_size;
255
256    s->frame.reference = 1;
257    s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
258    if (avctx->reget_buffer(avctx, &s->frame)) {
259        av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
260        return -1;
261    }
262
263    rpza_decode_stream(s);
264
265    *data_size = sizeof(AVFrame);
266    *(AVFrame*)data = s->frame;
267
268    /* always report that the buffer was completely consumed */
269    return buf_size;
270}
271
272static av_cold int rpza_decode_end(AVCodecContext *avctx)
273{
274    RpzaContext *s = avctx->priv_data;
275
276    if (s->frame.data[0])
277        avctx->release_buffer(avctx, &s->frame);
278
279    return 0;
280}
281
282AVCodec ff_rpza_decoder = {
283    .name           = "rpza",
284    .type           = AVMEDIA_TYPE_VIDEO,
285    .id             = CODEC_ID_RPZA,
286    .priv_data_size = sizeof(RpzaContext),
287    .init           = rpza_decode_init,
288    .close          = rpza_decode_end,
289    .decode         = rpza_decode_frame,
290    .capabilities   = CODEC_CAP_DR1,
291    .long_name = NULL_IF_CONFIG_SMALL("QuickTime video (RPZA)"),
292};
293