2 * Quicktime Video (RPZA) Video Decoder
3 * Copyright (C) 2003 the ffmpeg project
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 * QT RPZA Video Decoder by Roberto Togni <rtogni@bresciaonline.it>
24 * For more information about the RPZA format, visit:
25 * http://www.pcisys.net/~melanson/codecs/
27 * The RPZA decoder outputs RGB555 colorspace data.
29 * Note that this decoder reads big endian RGB555 pixel values from the
30 * bytestream, arranges them in the host's endian order, and outputs
31 * them to the final rendered map in the same host endian order. This is
32 * intended behavior as the ffmpeg documentation states that RGB555 pixels
33 * shall be stored in native CPU endianness.
45 typedef struct RpzaContext {
47 AVCodecContext *avctx;
57 #define BE_16(x) ((((uint8_t*)(x))[0] << 8) | ((uint8_t*)(x))[1])
58 #define BE_32(x) ((((uint8_t*)(x))[0] << 24) | \
59 (((uint8_t*)(x))[1] << 16) | \
60 (((uint8_t*)(x))[2] << 8) | \
63 #define ADVANCE_BLOCK() \
66 if (pixel_ptr >= width) \
69 row_ptr += stride * 4; \
72 if (total_blocks < 0) \
74 printf("warning: block counter just went negative (this should not happen)\n"); \
79 static void rpza_decode_stream(RpzaContext *s)
81 int width = s->avctx->width;
82 int stride = s->frame.linesize[0] / 2;
83 int row_inc = stride - 4;
88 unsigned short colorA = 0, colorB;
89 unsigned short color4[4];
90 unsigned char index, idx;
91 unsigned short ta, tb;
92 unsigned short *pixels = (unsigned short *)s->frame.data[0];
93 unsigned short *prev_pixels = (unsigned short *)s->prev_frame.data[0];
101 /* First byte is always 0xe1. Warn if it's different */
102 if (s->buf[stream_ptr] != 0xe1)
103 printf("First chunk byte is 0x%02x instead of 0x1e\n",
106 /* Get chunk size, ingnoring first byte */
107 chunk_size = BE_32(&s->buf[stream_ptr]) & 0x00FFFFFF;
110 /* If length mismatch use size from MOV file and try to decode anyway */
111 if (chunk_size != s->size)
112 printf("MOV chunk size != encoded chunk size; using MOV chunk size\n");
114 chunk_size = s->size;
116 /* Number of 4x4 blocks in frame. */
117 total_blocks = (s->avctx->width * s->avctx->height) / (4 * 4);
119 /* Process chunk data */
120 while (stream_ptr < chunk_size) {
121 opcode = s->buf[stream_ptr++]; /* Get opcode */
123 n_blocks = (opcode & 0x1f) + 1; /* Extract block counter from opcode */
125 /* If opcode MSbit is 0, we need more data to decide what to do */
126 if ((opcode & 0x80) == 0) {
127 colorA = (opcode << 8) | (s->buf[stream_ptr++]);
129 if ((s->buf[stream_ptr] & 0x80) != 0) {
130 /* Must behave as opcode 110xxxxx, using colorA computed
131 * above. Use fake opcode 0x20 to enter switch block at
138 switch (opcode & 0xe0) {
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] = prev_pixels[block_ptr];
149 block_ptr += row_inc;
155 /* Fill blocks with one color */
157 colorA = BE_16 (&s->buf[stream_ptr]);
160 block_ptr = row_ptr + pixel_ptr;
161 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
162 for (pixel_x = 0; pixel_x < 4; pixel_x++){
163 pixels[block_ptr] = colorA;
166 block_ptr += row_inc;
172 /* Fill blocks with 4 colors */
174 colorA = BE_16 (&s->buf[stream_ptr]);
177 colorB = BE_16 (&s->buf[stream_ptr]);
180 /* sort out the colors */
187 ta = (colorA >> 10) & 0x1F;
188 tb = (colorB >> 10) & 0x1F;
189 color4[1] |= ((11 * ta + 21 * tb) >> 5) << 10;
190 color4[2] |= ((21 * ta + 11 * tb) >> 5) << 10;
192 /* green components */
193 ta = (colorA >> 5) & 0x1F;
194 tb = (colorB >> 5) & 0x1F;
195 color4[1] |= ((11 * ta + 21 * tb) >> 5) << 5;
196 color4[2] |= ((21 * ta + 11 * tb) >> 5) << 5;
198 /* blue components */
201 color4[1] |= ((11 * ta + 21 * tb) >> 5);
202 color4[2] |= ((21 * ta + 11 * tb) >> 5);
205 block_ptr = row_ptr + pixel_ptr;
206 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
207 index = s->buf[stream_ptr++];
208 for (pixel_x = 0; pixel_x < 4; pixel_x++){
209 idx = (index >> (2 * (3 - pixel_x))) & 0x03;
210 pixels[block_ptr] = color4[idx];
213 block_ptr += row_inc;
219 /* Fill block with 16 colors */
221 block_ptr = row_ptr + pixel_ptr;
222 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
223 for (pixel_x = 0; pixel_x < 4; pixel_x++){
224 /* We already have color of upper left pixel */
225 if ((pixel_y != 0) || (pixel_x !=0)) {
226 colorA = BE_16 (&s->buf[stream_ptr]);
229 pixels[block_ptr] = colorA;
232 block_ptr += row_inc;
239 printf("Unknown opcode %d in rpza chunk."
240 " Skip remaining %d bytes of chunk data.\n", opcode,
241 chunk_size - stream_ptr);
243 } /* Opcode switch */
247 static int rpza_decode_init(AVCodecContext *avctx)
249 RpzaContext *s = (RpzaContext *)avctx->priv_data;
252 avctx->pix_fmt = PIX_FMT_RGB555;
253 avctx->has_b_frames = 0;
254 dsputil_init(&s->dsp, avctx);
256 s->frame.data[0] = s->prev_frame.data[0] = NULL;
261 static int rpza_decode_frame(AVCodecContext *avctx,
262 void *data, int *data_size,
263 uint8_t *buf, int buf_size)
265 RpzaContext *s = (RpzaContext *)avctx->priv_data;
270 if (avctx->get_buffer(avctx, &s->frame)) {
271 printf (" RPZA Video: get_buffer() failed\n");
275 rpza_decode_stream(s);
277 if (s->prev_frame.data[0])
278 avctx->release_buffer(avctx, &s->prev_frame);
281 s->prev_frame = s->frame;
283 *data_size = sizeof(AVFrame);
284 *(AVFrame*)data = s->frame;
286 /* always report that the buffer was completely consumed */
290 static int rpza_decode_end(AVCodecContext *avctx)
292 RpzaContext *s = (RpzaContext *)avctx->priv_data;
294 if (s->prev_frame.data[0])
295 avctx->release_buffer(avctx, &s->prev_frame);
300 AVCodec rpza_decoder = {