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/libavcodec/yop.c

http://github.com/FFmpeg/FFmpeg
C | 277 lines | 184 code | 43 blank | 50 comment | 22 complexity | 5cd380276a4b932f85407628b1160bbe MD5 | raw file
  1/*
  2 * Psygnosis YOP decoder
  3 *
  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>
  7 *
  8 * This file is part of FFmpeg.
  9 *
 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.
 14 *
 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.
 19 *
 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
 23 */
 24
 25#include <string.h>
 26
 27#include "libavutil/imgutils.h"
 28#include "libavutil/internal.h"
 29#include "libavutil/intreadwrite.h"
 30
 31#include "avcodec.h"
 32#include "internal.h"
 33
 34typedef struct YopDecContext {
 35    AVCodecContext *avctx;
 36    AVFrame *frame;
 37
 38    int num_pal_colors;
 39    int first_color[2];
 40    int frame_data_length;
 41
 42    uint8_t *low_nibble;
 43    uint8_t *srcptr;
 44    uint8_t *src_end;
 45    uint8_t *dstptr;
 46    uint8_t *dstbuf;
 47} YopDecContext;
 48
 49// These tables are taken directly from:
 50// http://wiki.multimedia.cx/index.php?title=Psygnosis_YOP
 51
 52/**
 53 * Lookup table for painting macroblocks. Bytes 0-2 of each entry contain
 54 * the macroblock positions to be painted (taken as (0, B0, B1, B2)).
 55 * Byte 3 contains the number of bytes consumed on the input,
 56 * equal to max(bytes 0-2) + 1.
 57 */
 58static const uint8_t paint_lut[15][4] =
 59    {{1, 2, 3, 4}, {1, 2, 0, 3},
 60     {1, 2, 1, 3}, {1, 2, 2, 3},
 61     {1, 0, 2, 3}, {1, 0, 0, 2},
 62     {1, 0, 1, 2}, {1, 1, 2, 3},
 63     {0, 1, 2, 3}, {0, 1, 0, 2},
 64     {1, 1, 0, 2}, {0, 1, 1, 2},
 65     {0, 0, 1, 2}, {0, 0, 0, 1},
 66     {1, 1, 1, 2},
 67    };
 68
 69/**
 70 * Lookup table for copying macroblocks. Each entry contains the respective
 71 * x and y pixel offset for the copy source.
 72 */
 73static const int8_t motion_vector[16][2] =
 74    {{-4, -4}, {-2, -4},
 75     { 0, -4}, { 2, -4},
 76     {-4, -2}, {-4,  0},
 77     {-3, -3}, {-1, -3},
 78     { 1, -3}, { 3, -3},
 79     {-3, -1}, {-2, -2},
 80     { 0, -2}, { 2, -2},
 81     { 4, -2}, {-2,  0},
 82    };
 83
 84static av_cold int yop_decode_close(AVCodecContext *avctx)
 85{
 86    YopDecContext *s = avctx->priv_data;
 87
 88    av_frame_free(&s->frame);
 89
 90    return 0;
 91}
 92
 93static av_cold int yop_decode_init(AVCodecContext *avctx)
 94{
 95    YopDecContext *s = avctx->priv_data;
 96    s->avctx = avctx;
 97
 98    if (avctx->width & 1 || avctx->height & 1 ||
 99        av_image_check_size(avctx->width, avctx->height, 0, avctx) < 0) {
100        av_log(avctx, AV_LOG_ERROR, "YOP has invalid dimensions\n");
101        return AVERROR_INVALIDDATA;
102    }
103
104    if (avctx->extradata_size < 3) {
105        av_log(avctx, AV_LOG_ERROR, "Missing or incomplete extradata.\n");
106        return AVERROR_INVALIDDATA;
107    }
108
109    avctx->pix_fmt = AV_PIX_FMT_PAL8;
110
111    s->num_pal_colors = avctx->extradata[0];
112    s->first_color[0] = avctx->extradata[1];
113    s->first_color[1] = avctx->extradata[2];
114
115    if (s->num_pal_colors + s->first_color[0] > 256 ||
116        s->num_pal_colors + s->first_color[1] > 256) {
117        av_log(avctx, AV_LOG_ERROR,
118               "Palette parameters invalid, header probably corrupt\n");
119        return AVERROR_INVALIDDATA;
120    }
121
122    s->frame = av_frame_alloc();
123    if (!s->frame)
124        return AVERROR(ENOMEM);
125
126    return 0;
127}
128
129/**
130 * Paint a macroblock using the pattern in paint_lut.
131 * @param s codec context
132 * @param tag the tag that was in the nibble
133 */
134static int yop_paint_block(YopDecContext *s, int linesize, int tag)
135{
136    if (s->src_end - s->srcptr < paint_lut[tag][3]) {
137        av_log(s->avctx, AV_LOG_ERROR, "Packet too small.\n");
138        return AVERROR_INVALIDDATA;
139    }
140
141    s->dstptr[0]            = s->srcptr[0];
142    s->dstptr[1]            = s->srcptr[paint_lut[tag][0]];
143    s->dstptr[linesize]     = s->srcptr[paint_lut[tag][1]];
144    s->dstptr[linesize + 1] = s->srcptr[paint_lut[tag][2]];
145
146    // The number of src bytes consumed is in the last part of the lut entry.
147    s->srcptr += paint_lut[tag][3];
148    return 0;
149}
150
151/**
152 * Copy a previously painted macroblock to the current_block.
153 * @param copy_tag the tag that was in the nibble
154 */
155static int yop_copy_previous_block(YopDecContext *s, int linesize, int copy_tag)
156{
157    uint8_t *bufptr;
158
159    // Calculate position for the copy source
160    bufptr = s->dstptr + motion_vector[copy_tag][0] +
161             linesize * motion_vector[copy_tag][1];
162    if (bufptr < s->dstbuf) {
163        av_log(s->avctx, AV_LOG_ERROR, "File probably corrupt\n");
164        return AVERROR_INVALIDDATA;
165    }
166
167    s->dstptr[0]            = bufptr[0];
168    s->dstptr[1]            = bufptr[1];
169    s->dstptr[linesize]     = bufptr[linesize];
170    s->dstptr[linesize + 1] = bufptr[linesize + 1];
171
172    return 0;
173}
174
175/**
176 * Return the next nibble in sequence, consuming a new byte on the input
177 * only if necessary.
178 */
179static uint8_t yop_get_next_nibble(YopDecContext *s)
180{
181    int ret;
182
183    if (s->low_nibble) {
184        ret           = *s->low_nibble & 0xf;
185        s->low_nibble = NULL;
186    }else {
187        s->low_nibble = s->srcptr++;
188        ret           = *s->low_nibble >> 4;
189    }
190    return ret;
191}
192
193static int yop_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
194                            AVPacket *avpkt)
195{
196    YopDecContext *s = avctx->priv_data;
197    AVFrame *frame = s->frame;
198    int tag, firstcolor, is_odd_frame;
199    int ret, i, x, y;
200    uint32_t *palette;
201
202    if (avpkt->size < 4 + 3 * s->num_pal_colors) {
203        av_log(avctx, AV_LOG_ERROR, "Packet too small.\n");
204        return AVERROR_INVALIDDATA;
205    }
206
207    if ((ret = ff_reget_buffer(avctx, frame, 0)) < 0)
208        return ret;
209
210    if (!avctx->frame_number)
211        memset(frame->data[1], 0, AVPALETTE_SIZE);
212
213    s->dstbuf     = frame->data[0];
214    s->dstptr     = frame->data[0];
215    s->srcptr     = avpkt->data + 4;
216    s->src_end    = avpkt->data + avpkt->size;
217    s->low_nibble = NULL;
218
219    is_odd_frame = avpkt->data[0];
220    if(is_odd_frame>1){
221        av_log(avctx, AV_LOG_ERROR, "frame is too odd %d\n", is_odd_frame);
222        return AVERROR_INVALIDDATA;
223    }
224    firstcolor   = s->first_color[is_odd_frame];
225    palette      = (uint32_t *)frame->data[1];
226
227    for (i = 0; i < s->num_pal_colors; i++, s->srcptr += 3) {
228        palette[i + firstcolor] = (s->srcptr[0] << 18) |
229                                  (s->srcptr[1] << 10) |
230                                  (s->srcptr[2] << 2);
231        palette[i + firstcolor] |= 0xFFU << 24 |
232                                   (palette[i + firstcolor] >> 6) & 0x30303;
233    }
234
235    frame->palette_has_changed = 1;
236
237    for (y = 0; y < avctx->height; y += 2) {
238        for (x = 0; x < avctx->width; x += 2) {
239            if (s->srcptr - avpkt->data >= avpkt->size) {
240                av_log(avctx, AV_LOG_ERROR, "Packet too small.\n");
241                return AVERROR_INVALIDDATA;
242            }
243
244            tag = yop_get_next_nibble(s);
245
246            if (tag != 0xf) {
247                ret = yop_paint_block(s, frame->linesize[0], tag);
248                if (ret < 0)
249                    return ret;
250            } else {
251                tag = yop_get_next_nibble(s);
252                ret = yop_copy_previous_block(s, frame->linesize[0], tag);
253                if (ret < 0)
254                    return ret;
255            }
256            s->dstptr += 2;
257        }
258        s->dstptr += 2*frame->linesize[0] - x;
259    }
260
261    if ((ret = av_frame_ref(data, s->frame)) < 0)
262        return ret;
263
264    *got_frame = 1;
265    return avpkt->size;
266}
267
268AVCodec ff_yop_decoder = {
269    .name           = "yop",
270    .long_name      = NULL_IF_CONFIG_SMALL("Psygnosis YOP Video"),
271    .type           = AVMEDIA_TYPE_VIDEO,
272    .id             = AV_CODEC_ID_YOP,
273    .priv_data_size = sizeof(YopDecContext),
274    .init           = yop_decode_init,
275    .close          = yop_decode_close,
276    .decode         = yop_decode_frame,
277};