2 * Psygnosis YOP decoder
4 * Copyright (C) 2010 Mohamed Naufal Basheer <naufal11@gmail.com>
5 * derived from the code by
6 * Copyright (C) 2009 Thomas P. Higdon <thomas.p.higdon@gmail.com>
8 * This file is part of FFmpeg.
10 * FFmpeg is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU Lesser General Public
12 * License as published by the Free Software Foundation; either
13 * version 2.1 of the License, or (at your option) any later version.
15 * FFmpeg is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * Lesser General Public License for more details.
20 * You should have received a copy of the GNU Lesser General Public
21 * License along with FFmpeg; if not, write to the Free Software
22 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25 #include "libavutil/intreadwrite.h"
26 #include "libavutil/imgutils.h"
32 typedef struct YopDecContext {
33 AVCodecContext *avctx;
38 int frame_data_length;
47 // These tables are taken directly from:
48 // http://wiki.multimedia.cx/index.php?title=Psygnosis_YOP
51 * Lookup table for painting macroblocks. Bytes 0-2 of each entry contain
52 * the macroblock positions to be painted (taken as (0, B0, B1, B2)).
53 * Byte 3 contains the number of bytes consumed on the input,
54 * equal to max(bytes 0-2) + 1.
56 static const uint8_t paint_lut[15][4] =
57 {{1, 2, 3, 4}, {1, 2, 0, 3},
58 {1, 2, 1, 3}, {1, 2, 2, 3},
59 {1, 0, 2, 3}, {1, 0, 0, 2},
60 {1, 0, 1, 2}, {1, 1, 2, 3},
61 {0, 1, 2, 3}, {0, 1, 0, 2},
62 {1, 1, 0, 2}, {0, 1, 1, 2},
63 {0, 0, 1, 2}, {0, 0, 0, 1},
68 * Lookup table for copying macroblocks. Each entry contains the respective
69 * x and y pixel offset for the copy source.
71 static const int8_t motion_vector[16][2] =
82 static av_cold int yop_decode_close(AVCodecContext *avctx)
84 YopDecContext *s = avctx->priv_data;
86 av_frame_free(&s->frame);
91 static av_cold int yop_decode_init(AVCodecContext *avctx)
93 YopDecContext *s = avctx->priv_data;
96 if (avctx->width & 1 || avctx->height & 1 ||
97 av_image_check_size(avctx->width, avctx->height, 0, avctx) < 0) {
98 av_log(avctx, AV_LOG_ERROR, "YOP has invalid dimensions\n");
99 return AVERROR_INVALIDDATA;
102 if (avctx->extradata_size < 3) {
103 av_log(avctx, AV_LOG_ERROR, "Missing or incomplete extradata.\n");
104 return AVERROR_INVALIDDATA;
107 avctx->pix_fmt = AV_PIX_FMT_PAL8;
109 s->num_pal_colors = avctx->extradata[0];
110 s->first_color[0] = avctx->extradata[1];
111 s->first_color[1] = avctx->extradata[2];
113 if (s->num_pal_colors + s->first_color[0] > 256 ||
114 s->num_pal_colors + s->first_color[1] > 256) {
115 av_log(avctx, AV_LOG_ERROR,
116 "Palette parameters invalid, header probably corrupt\n");
117 return AVERROR_INVALIDDATA;
120 s->frame = av_frame_alloc();
126 * Paint a macroblock using the pattern in paint_lut.
127 * @param s codec context
128 * @param tag the tag that was in the nibble
130 static int yop_paint_block(YopDecContext *s, int linesize, int tag)
132 if (s->src_end - s->srcptr < paint_lut[tag][3]) {
133 av_log(s->avctx, AV_LOG_ERROR, "Packet too small.\n");
134 return AVERROR_INVALIDDATA;
137 s->dstptr[0] = s->srcptr[0];
138 s->dstptr[1] = s->srcptr[paint_lut[tag][0]];
139 s->dstptr[linesize] = s->srcptr[paint_lut[tag][1]];
140 s->dstptr[linesize + 1] = s->srcptr[paint_lut[tag][2]];
142 // The number of src bytes consumed is in the last part of the lut entry.
143 s->srcptr += paint_lut[tag][3];
148 * Copy a previously painted macroblock to the current_block.
149 * @param copy_tag the tag that was in the nibble
151 static int yop_copy_previous_block(YopDecContext *s, int linesize, int copy_tag)
155 // Calculate position for the copy source
156 bufptr = s->dstptr + motion_vector[copy_tag][0] +
157 linesize * motion_vector[copy_tag][1];
158 if (bufptr < s->dstbuf) {
159 av_log(s->avctx, AV_LOG_ERROR, "File probably corrupt\n");
160 return AVERROR_INVALIDDATA;
163 s->dstptr[0] = bufptr[0];
164 s->dstptr[1] = bufptr[1];
165 s->dstptr[linesize] = bufptr[linesize];
166 s->dstptr[linesize + 1] = bufptr[linesize + 1];
172 * Return the next nibble in sequence, consuming a new byte on the input
175 static uint8_t yop_get_next_nibble(YopDecContext *s)
180 ret = *s->low_nibble & 0xf;
181 s->low_nibble = NULL;
183 s->low_nibble = s->srcptr++;
184 ret = *s->low_nibble >> 4;
189 static int yop_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
192 YopDecContext *s = avctx->priv_data;
193 AVFrame *frame = s->frame;
194 int tag, firstcolor, is_odd_frame;
198 if (avpkt->size < 4 + 3 * s->num_pal_colors) {
199 av_log(avctx, AV_LOG_ERROR, "Packet too small.\n");
200 return AVERROR_INVALIDDATA;
203 if ((ret = ff_reget_buffer(avctx, frame)) < 0)
206 if (!avctx->frame_number)
207 memset(frame->data[1], 0, AVPALETTE_SIZE);
209 s->dstbuf = frame->data[0];
210 s->dstptr = frame->data[0];
211 s->srcptr = avpkt->data + 4;
212 s->src_end = avpkt->data + avpkt->size;
213 s->low_nibble = NULL;
215 is_odd_frame = avpkt->data[0];
217 av_log(avctx, AV_LOG_ERROR, "frame is too odd %d\n", is_odd_frame);
218 return AVERROR_INVALIDDATA;
220 firstcolor = s->first_color[is_odd_frame];
221 palette = (uint32_t *)frame->data[1];
223 for (i = 0; i < s->num_pal_colors; i++, s->srcptr += 3) {
224 palette[i + firstcolor] = (s->srcptr[0] << 18) |
225 (s->srcptr[1] << 10) |
227 palette[i + firstcolor] |= 0xFFU << 24 |
228 (palette[i + firstcolor] >> 6) & 0x30303;
231 frame->palette_has_changed = 1;
233 for (y = 0; y < avctx->height; y += 2) {
234 for (x = 0; x < avctx->width; x += 2) {
235 if (s->srcptr - avpkt->data >= avpkt->size) {
236 av_log(avctx, AV_LOG_ERROR, "Packet too small.\n");
237 return AVERROR_INVALIDDATA;
240 tag = yop_get_next_nibble(s);
243 ret = yop_paint_block(s, frame->linesize[0], tag);
247 tag = yop_get_next_nibble(s);
248 ret = yop_copy_previous_block(s, frame->linesize[0], tag);
254 s->dstptr += 2*frame->linesize[0] - x;
257 if ((ret = av_frame_ref(data, s->frame)) < 0)
264 AVCodec ff_yop_decoder = {
266 .type = AVMEDIA_TYPE_VIDEO,
267 .id = AV_CODEC_ID_YOP,
268 .priv_data_size = sizeof(YopDecContext),
269 .init = yop_decode_init,
270 .close = yop_decode_close,
271 .decode = yop_decode_frame,
272 .long_name = NULL_IF_CONFIG_SMALL("Psygnosis YOP Video"),