FFmpeg: libavcodec/motionpixels.c Source File

00001 /*
00002  * Motion Pixels Video Decoder
00003  * Copyright (c) 2008 Gregory Montoir (cyx@users.sourceforge.net)
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 #include "avcodec.h"
00023 #include "get_bits.h"
00024 #include "dsputil.h"
00025 
00026 #define MAX_HUFF_CODES 16
00027 
00028 #include "motionpixels_tablegen.h"
00029 
00030 typedef struct HuffCode {
00031     int code;
00032     uint8_t size;
00033     uint8_t delta;
00034 } HuffCode;
00035 
00036 typedef struct MotionPixelsContext {
00037     AVCodecContext *avctx;
00038     AVFrame frame;
00039     DSPContext dsp;
00040     uint8_t *changes_map;
00041     int offset_bits_len;
00042     int codes_count, current_codes_count;
00043     int max_codes_bits;
00044     HuffCode codes[MAX_HUFF_CODES];
00045     VLC vlc;
00046     YuvPixel *vpt, *hpt;
00047     uint8_t gradient_scale[3];
00048     uint8_t *bswapbuf;
00049     int bswapbuf_size;
00050 } MotionPixelsContext;
00051 
00052 static av_cold int mp_decode_init(AVCodecContext *avctx)
00053 {
00054     MotionPixelsContext *mp = avctx->priv_data;
00055     int w4 = (avctx->width  + 3) & ~3;
00056     int h4 = (avctx->height + 3) & ~3;
00057 
00058     if(avctx->extradata_size < 2){
00059         av_log(avctx, AV_LOG_ERROR, "extradata too small\n");
00060         return AVERROR_INVALIDDATA;
00061     }
00062 
00063     motionpixels_tableinit();
00064     mp->avctx = avctx;
00065     dsputil_init(&mp->dsp, avctx);
00066     mp->changes_map = av_mallocz(avctx->width * h4);
00067     mp->offset_bits_len = av_log2(avctx->width * avctx->height) + 1;
00068     mp->vpt = av_mallocz(avctx->height * sizeof(YuvPixel));
00069     mp->hpt = av_mallocz(h4 * w4 / 16 * sizeof(YuvPixel));
00070     avctx->pix_fmt = PIX_FMT_RGB555;
00071     avcodec_get_frame_defaults(&mp->frame);
00072     return 0;
00073 }
00074 
00075 static void mp_read_changes_map(MotionPixelsContext *mp, GetBitContext *gb, int count, int bits_len, int read_color)
00076 {
00077     uint16_t *pixels;
00078     int offset, w, h, color = 0, x, y, i;
00079 
00080     while (count--) {
00081         offset = get_bits_long(gb, mp->offset_bits_len);
00082         w      = get_bits(gb, bits_len) + 1;
00083         h      = get_bits(gb, bits_len) + 1;
00084         if (read_color)
00085             color = get_bits(gb, 15);
00086         x = offset % mp->avctx->width;
00087         y = offset / mp->avctx->width;
00088         if (y >= mp->avctx->height)
00089             continue;
00090         w = FFMIN(w, mp->avctx->width  - x);
00091         h = FFMIN(h, mp->avctx->height - y);
00092         pixels = (uint16_t *)&mp->frame.data[0][y * mp->frame.linesize[0] + x * 2];
00093         while (h--) {
00094             mp->changes_map[offset] = w;
00095             if (read_color)
00096                 for (i = 0; i < w; ++i)
00097                     pixels[i] = color;
00098             offset += mp->avctx->width;
00099             pixels += mp->frame.linesize[0] / 2;
00100         }
00101     }
00102 }
00103 
00104 static void mp_get_code(MotionPixelsContext *mp, GetBitContext *gb, int size, int code)
00105 {
00106     while (get_bits1(gb)) {
00107         ++size;
00108         if (size > mp->max_codes_bits) {
00109             av_log(mp->avctx, AV_LOG_ERROR, "invalid code size %d/%d\n", size, mp->max_codes_bits);
00110             return;
00111         }
00112         code <<= 1;
00113         mp_get_code(mp, gb, size, code + 1);
00114     }
00115     if (mp->current_codes_count >= MAX_HUFF_CODES) {
00116         av_log(mp->avctx, AV_LOG_ERROR, "too many codes\n");
00117         return;
00118     }
00119     mp->codes[mp->current_codes_count  ].code = code;
00120     mp->codes[mp->current_codes_count++].size = size;
00121 }
00122 
00123 static void mp_read_codes_table(MotionPixelsContext *mp, GetBitContext *gb)
00124 {
00125     if (mp->codes_count == 1) {
00126         mp->codes[0].delta = get_bits(gb, 4);
00127     } else {
00128         int i;
00129 
00130         mp->max_codes_bits = get_bits(gb, 4);
00131         for (i = 0; i < mp->codes_count; ++i)
00132             mp->codes[i].delta = get_bits(gb, 4);
00133         mp->current_codes_count = 0;
00134         mp_get_code(mp, gb, 0, 0);
00135    }
00136 }
00137 
00138 static int mp_gradient(MotionPixelsContext *mp, int component, int v)
00139 {
00140     int delta;
00141 
00142     delta = (v - 7) * mp->gradient_scale[component];
00143     mp->gradient_scale[component] = (v == 0 || v == 14) ? 2 : 1;
00144     return delta;
00145 }
00146 
00147 static YuvPixel mp_get_yuv_from_rgb(MotionPixelsContext *mp, int x, int y)
00148 {
00149     int color;
00150 
00151     color = *(uint16_t *)&mp->frame.data[0][y * mp->frame.linesize[0] + x * 2];
00152     return mp_rgb_yuv_table[color];
00153 }
00154 
00155 static void mp_set_rgb_from_yuv(MotionPixelsContext *mp, int x, int y, const YuvPixel *p)
00156 {
00157     int color;
00158 
00159     color = mp_yuv_to_rgb(p->y, p->v, p->u, 1);
00160     *(uint16_t *)&mp->frame.data[0][y * mp->frame.linesize[0] + x * 2] = color;
00161 }
00162 
00163 static int mp_get_vlc(MotionPixelsContext *mp, GetBitContext *gb)
00164 {
00165     int i;
00166 
00167     i = (mp->codes_count == 1) ? 0 : get_vlc2(gb, mp->vlc.table, mp->max_codes_bits, 1);
00168     return mp->codes[i].delta;
00169 }
00170 
00171 static void mp_decode_line(MotionPixelsContext *mp, GetBitContext *gb, int y)
00172 {
00173     YuvPixel p;
00174     const int y0 = y * mp->avctx->width;
00175     int w, i, x = 0;
00176 
00177     p = mp->vpt[y];
00178     if (mp->changes_map[y0 + x] == 0) {
00179         memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));
00180         ++x;
00181     }
00182     while (x < mp->avctx->width) {
00183         w = mp->changes_map[y0 + x];
00184         if (w != 0) {
00185             if ((y & 3) == 0) {
00186                 if (mp->changes_map[y0 + x + mp->avctx->width] < w ||
00187                     mp->changes_map[y0 + x + mp->avctx->width * 2] < w ||
00188                     mp->changes_map[y0 + x + mp->avctx->width * 3] < w) {
00189                     for (i = (x + 3) & ~3; i < x + w; i += 4) {
00190                         mp->hpt[((y / 4) * mp->avctx->width + i) / 4] = mp_get_yuv_from_rgb(mp, i, y);
00191                     }
00192                 }
00193             }
00194             x += w;
00195             memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));
00196             p = mp_get_yuv_from_rgb(mp, x - 1, y);
00197         } else {
00198             p.y += mp_gradient(mp, 0, mp_get_vlc(mp, gb));
00199             p.y = av_clip(p.y, 0, 31);
00200             if ((x & 3) == 0) {
00201                 if ((y & 3) == 0) {
00202                     p.v += mp_gradient(mp, 1, mp_get_vlc(mp, gb));
00203                     p.v = av_clip(p.v, -32, 31);
00204                     p.u += mp_gradient(mp, 2, mp_get_vlc(mp, gb));
00205                     p.u = av_clip(p.u, -32, 31);
00206                     mp->hpt[((y / 4) * mp->avctx->width + x) / 4] = p;
00207                 } else {
00208                     p.v = mp->hpt[((y / 4) * mp->avctx->width + x) / 4].v;
00209                     p.u = mp->hpt[((y / 4) * mp->avctx->width + x) / 4].u;
00210                 }
00211             }
00212             mp_set_rgb_from_yuv(mp, x, y, &p);
00213             ++x;
00214         }
00215     }
00216 }
00217 
00218 static void mp_decode_frame_helper(MotionPixelsContext *mp, GetBitContext *gb)
00219 {
00220     YuvPixel p;
00221     int y, y0;
00222 
00223     for (y = 0; y < mp->avctx->height; ++y) {
00224         if (mp->changes_map[y * mp->avctx->width] != 0) {
00225             memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));
00226             p = mp_get_yuv_from_rgb(mp, 0, y);
00227         } else {
00228             p.y += mp_gradient(mp, 0, mp_get_vlc(mp, gb));
00229             p.y = av_clip(p.y, 0, 31);
00230             if ((y & 3) == 0) {
00231                 p.v += mp_gradient(mp, 1, mp_get_vlc(mp, gb));
00232                 p.v = av_clip(p.v, -32, 31);
00233                 p.u += mp_gradient(mp, 2, mp_get_vlc(mp, gb));
00234                 p.u = av_clip(p.u, -32, 31);
00235             }
00236             mp->vpt[y] = p;
00237             mp_set_rgb_from_yuv(mp, 0, y, &p);
00238         }
00239     }
00240     for (y0 = 0; y0 < 2; ++y0)
00241         for (y = y0; y < mp->avctx->height; y += 2)
00242             mp_decode_line(mp, gb, y);
00243 }
00244 
00245 static int mp_decode_frame(AVCodecContext *avctx,
00246                                  void *data, int *data_size,
00247                                  AVPacket *avpkt)
00248 {
00249     const uint8_t *buf = avpkt->data;
00250     int buf_size = avpkt->size;
00251     MotionPixelsContext *mp = avctx->priv_data;
00252     GetBitContext gb;
00253     int i, count1, count2, sz;
00254 
00255     mp->frame.reference = 1;
00256     mp->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
00257     if (avctx->reget_buffer(avctx, &mp->frame)) {
00258         av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
00259         return -1;
00260     }
00261 
00262     /* le32 bitstream msb first */
00263     av_fast_malloc(&mp->bswapbuf, &mp->bswapbuf_size, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
00264     if (!mp->bswapbuf)
00265         return AVERROR(ENOMEM);
00266     mp->dsp.bswap_buf((uint32_t *)mp->bswapbuf, (const uint32_t *)buf, buf_size / 4);
00267     if (buf_size & 3)
00268         memcpy(mp->bswapbuf + (buf_size & ~3), buf + (buf_size & ~3), buf_size & 3);
00269     memset(mp->bswapbuf + buf_size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
00270     init_get_bits(&gb, mp->bswapbuf, buf_size * 8);
00271 
00272     memset(mp->changes_map, 0, avctx->width * avctx->height);
00273     for (i = !(avctx->extradata[1] & 2); i < 2; ++i) {
00274         count1 = get_bits(&gb, 12);
00275         count2 = get_bits(&gb, 12);
00276         mp_read_changes_map(mp, &gb, count1, 8, i);
00277         mp_read_changes_map(mp, &gb, count2, 4, i);
00278     }
00279 
00280     mp->codes_count = get_bits(&gb, 4);
00281     if (mp->codes_count == 0)
00282         goto end;
00283 
00284     if (mp->changes_map[0] == 0) {
00285         *(uint16_t *)mp->frame.data[0] = get_bits(&gb, 15);
00286         mp->changes_map[0] = 1;
00287     }
00288     mp_read_codes_table(mp, &gb);
00289 
00290     sz = get_bits(&gb, 18);
00291     if (avctx->extradata[0] != 5)
00292         sz += get_bits(&gb, 18);
00293     if (sz == 0)
00294         goto end;
00295 
00296     if (mp->max_codes_bits <= 0)
00297         goto end;
00298     if (init_vlc(&mp->vlc, mp->max_codes_bits, mp->codes_count, &mp->codes[0].size, sizeof(HuffCode), 1, &mp->codes[0].code, sizeof(HuffCode), 4, 0))
00299         goto end;
00300     mp_decode_frame_helper(mp, &gb);
00301     free_vlc(&mp->vlc);
00302 
00303 end:
00304     *data_size = sizeof(AVFrame);
00305     *(AVFrame *)data = mp->frame;
00306     return buf_size;
00307 }
00308 
00309 static av_cold int mp_decode_end(AVCodecContext *avctx)
00310 {
00311     MotionPixelsContext *mp = avctx->priv_data;
00312 
00313     av_freep(&mp->changes_map);
00314     av_freep(&mp->vpt);
00315     av_freep(&mp->hpt);
00316     av_freep(&mp->bswapbuf);
00317     if (mp->frame.data[0])
00318         avctx->release_buffer(avctx, &mp->frame);
00319 
00320     return 0;
00321 }
00322 
00323 AVCodec ff_motionpixels_decoder = {
00324     "motionpixels",
00325     AVMEDIA_TYPE_VIDEO,
00326     CODEC_ID_MOTIONPIXELS,
00327     sizeof(MotionPixelsContext),
00328     mp_decode_init,
00329     NULL,
00330     mp_decode_end,
00331     mp_decode_frame,
00332     CODEC_CAP_DR1,
00333     .long_name = NULL_IF_CONFIG_SMALL("Motion Pixels video"),
00334 };