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libavcodec/motionpixels.c

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00001 /*
00002  * Motion Pixels Video Decoder
00003  * Copyright (c) 2008 Gregory Montoir (cyx@users.sourceforge.net)
00004  *
00005  * This file is part of Libav.
00006  *
00007  * Libav 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  * Libav 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 Libav; 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     motionpixels_tableinit();
00059     mp->avctx = avctx;
00060     dsputil_init(&mp->dsp, avctx);
00061     mp->changes_map = av_mallocz(avctx->width * h4);
00062     mp->offset_bits_len = av_log2(avctx->width * avctx->height) + 1;
00063     mp->vpt = av_mallocz(avctx->height * sizeof(YuvPixel));
00064     mp->hpt = av_mallocz(h4 * w4 / 16 * sizeof(YuvPixel));
00065     avctx->pix_fmt = PIX_FMT_RGB555;
00066     return 0;
00067 }
00068 
00069 static void mp_read_changes_map(MotionPixelsContext *mp, GetBitContext *gb, int count, int bits_len, int read_color)
00070 {
00071     uint16_t *pixels;
00072     int offset, w, h, color = 0, x, y, i;
00073 
00074     while (count--) {
00075         offset = get_bits_long(gb, mp->offset_bits_len);
00076         w      = get_bits(gb, bits_len) + 1;
00077         h      = get_bits(gb, bits_len) + 1;
00078         if (read_color)
00079             color = get_bits(gb, 15);
00080         x = offset % mp->avctx->width;
00081         y = offset / mp->avctx->width;
00082         if (y >= mp->avctx->height)
00083             continue;
00084         w = FFMIN(w, mp->avctx->width  - x);
00085         h = FFMIN(h, mp->avctx->height - y);
00086         pixels = (uint16_t *)&mp->frame.data[0][y * mp->frame.linesize[0] + x * 2];
00087         while (h--) {
00088             mp->changes_map[offset] = w;
00089             if (read_color)
00090                 for (i = 0; i < w; ++i)
00091                     pixels[i] = color;
00092             offset += mp->avctx->width;
00093             pixels += mp->frame.linesize[0] / 2;
00094         }
00095     }
00096 }
00097 
00098 static void mp_get_code(MotionPixelsContext *mp, GetBitContext *gb, int size, int code)
00099 {
00100     while (get_bits1(gb)) {
00101         ++size;
00102         if (size > mp->max_codes_bits) {
00103             av_log(mp->avctx, AV_LOG_ERROR, "invalid code size %d/%d\n", size, mp->max_codes_bits);
00104             return;
00105         }
00106         code <<= 1;
00107         mp_get_code(mp, gb, size, code + 1);
00108     }
00109     if (mp->current_codes_count >= MAX_HUFF_CODES) {
00110         av_log(mp->avctx, AV_LOG_ERROR, "too many codes\n");
00111         return;
00112     }
00113     mp->codes[mp->current_codes_count  ].code = code;
00114     mp->codes[mp->current_codes_count++].size = size;
00115 }
00116 
00117 static void mp_read_codes_table(MotionPixelsContext *mp, GetBitContext *gb)
00118 {
00119     if (mp->codes_count == 1) {
00120         mp->codes[0].delta = get_bits(gb, 4);
00121     } else {
00122         int i;
00123 
00124         mp->max_codes_bits = get_bits(gb, 4);
00125         for (i = 0; i < mp->codes_count; ++i)
00126             mp->codes[i].delta = get_bits(gb, 4);
00127         mp->current_codes_count = 0;
00128         mp_get_code(mp, gb, 0, 0);
00129    }
00130 }
00131 
00132 static int mp_gradient(MotionPixelsContext *mp, int component, int v)
00133 {
00134     int delta;
00135 
00136     delta = (v - 7) * mp->gradient_scale[component];
00137     mp->gradient_scale[component] = (v == 0 || v == 14) ? 2 : 1;
00138     return delta;
00139 }
00140 
00141 static YuvPixel mp_get_yuv_from_rgb(MotionPixelsContext *mp, int x, int y)
00142 {
00143     int color;
00144 
00145     color = *(uint16_t *)&mp->frame.data[0][y * mp->frame.linesize[0] + x * 2];
00146     return mp_rgb_yuv_table[color];
00147 }
00148 
00149 static void mp_set_rgb_from_yuv(MotionPixelsContext *mp, int x, int y, const YuvPixel *p)
00150 {
00151     int color;
00152 
00153     color = mp_yuv_to_rgb(p->y, p->v, p->u, 1);
00154     *(uint16_t *)&mp->frame.data[0][y * mp->frame.linesize[0] + x * 2] = color;
00155 }
00156 
00157 static int mp_get_vlc(MotionPixelsContext *mp, GetBitContext *gb)
00158 {
00159     int i;
00160 
00161     i = (mp->codes_count == 1) ? 0 : get_vlc2(gb, mp->vlc.table, mp->max_codes_bits, 1);
00162     return mp->codes[i].delta;
00163 }
00164 
00165 static void mp_decode_line(MotionPixelsContext *mp, GetBitContext *gb, int y)
00166 {
00167     YuvPixel p;
00168     const int y0 = y * mp->avctx->width;
00169     int w, i, x = 0;
00170 
00171     p = mp->vpt[y];
00172     if (mp->changes_map[y0 + x] == 0) {
00173         memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));
00174         ++x;
00175     }
00176     while (x < mp->avctx->width) {
00177         w = mp->changes_map[y0 + x];
00178         if (w != 0) {
00179             if ((y & 3) == 0) {
00180                 if (mp->changes_map[y0 + x + mp->avctx->width] < w ||
00181                     mp->changes_map[y0 + x + mp->avctx->width * 2] < w ||
00182                     mp->changes_map[y0 + x + mp->avctx->width * 3] < w) {
00183                     for (i = (x + 3) & ~3; i < x + w; i += 4) {
00184                         mp->hpt[((y / 4) * mp->avctx->width + i) / 4] = mp_get_yuv_from_rgb(mp, i, y);
00185                     }
00186                 }
00187             }
00188             x += w;
00189             memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));
00190             p = mp_get_yuv_from_rgb(mp, x - 1, y);
00191         } else {
00192             p.y += mp_gradient(mp, 0, mp_get_vlc(mp, gb));
00193             if ((x & 3) == 0) {
00194                 if ((y & 3) == 0) {
00195                     p.v += mp_gradient(mp, 1, mp_get_vlc(mp, gb));
00196                     p.u += mp_gradient(mp, 2, mp_get_vlc(mp, gb));
00197                     mp->hpt[((y / 4) * mp->avctx->width + x) / 4] = p;
00198                 } else {
00199                     p.v = mp->hpt[((y / 4) * mp->avctx->width + x) / 4].v;
00200                     p.u = mp->hpt[((y / 4) * mp->avctx->width + x) / 4].u;
00201                 }
00202             }
00203             mp_set_rgb_from_yuv(mp, x, y, &p);
00204             ++x;
00205         }
00206     }
00207 }
00208 
00209 static void mp_decode_frame_helper(MotionPixelsContext *mp, GetBitContext *gb)
00210 {
00211     YuvPixel p;
00212     int y, y0;
00213 
00214     for (y = 0; y < mp->avctx->height; ++y) {
00215         if (mp->changes_map[y * mp->avctx->width] != 0) {
00216             memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));
00217             p = mp_get_yuv_from_rgb(mp, 0, y);
00218         } else {
00219             p.y += mp_gradient(mp, 0, mp_get_vlc(mp, gb));
00220             if ((y & 3) == 0) {
00221                 p.v += mp_gradient(mp, 1, mp_get_vlc(mp, gb));
00222                 p.u += mp_gradient(mp, 2, mp_get_vlc(mp, gb));
00223             }
00224             mp->vpt[y] = p;
00225             mp_set_rgb_from_yuv(mp, 0, y, &p);
00226         }
00227     }
00228     for (y0 = 0; y0 < 2; ++y0)
00229         for (y = y0; y < mp->avctx->height; y += 2)
00230             mp_decode_line(mp, gb, y);
00231 }
00232 
00233 static int mp_decode_frame(AVCodecContext *avctx,
00234                                  void *data, int *data_size,
00235                                  AVPacket *avpkt)
00236 {
00237     const uint8_t *buf = avpkt->data;
00238     int buf_size = avpkt->size;
00239     MotionPixelsContext *mp = avctx->priv_data;
00240     GetBitContext gb;
00241     int i, count1, count2, sz;
00242 
00243     mp->frame.reference = 1;
00244     mp->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
00245     if (avctx->reget_buffer(avctx, &mp->frame)) {
00246         av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
00247         return -1;
00248     }
00249 
00250     /* le32 bitstream msb first */
00251     av_fast_malloc(&mp->bswapbuf, &mp->bswapbuf_size, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
00252     if (!mp->bswapbuf)
00253         return AVERROR(ENOMEM);
00254     mp->dsp.bswap_buf((uint32_t *)mp->bswapbuf, (const uint32_t *)buf, buf_size / 4);
00255     if (buf_size & 3)
00256         memcpy(mp->bswapbuf + (buf_size & ~3), buf + (buf_size & ~3), buf_size & 3);
00257     memset(mp->bswapbuf + buf_size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
00258     init_get_bits(&gb, mp->bswapbuf, buf_size * 8);
00259 
00260     memset(mp->changes_map, 0, avctx->width * avctx->height);
00261     for (i = !(avctx->extradata[1] & 2); i < 2; ++i) {
00262         count1 = get_bits(&gb, 12);
00263         count2 = get_bits(&gb, 12);
00264         mp_read_changes_map(mp, &gb, count1, 8, i);
00265         mp_read_changes_map(mp, &gb, count2, 4, i);
00266     }
00267 
00268     mp->codes_count = get_bits(&gb, 4);
00269     if (mp->codes_count == 0)
00270         goto end;
00271 
00272     if (mp->changes_map[0] == 0) {
00273         *(uint16_t *)mp->frame.data[0] = get_bits(&gb, 15);
00274         mp->changes_map[0] = 1;
00275     }
00276     mp_read_codes_table(mp, &gb);
00277 
00278     sz = get_bits(&gb, 18);
00279     if (avctx->extradata[0] != 5)
00280         sz += get_bits(&gb, 18);
00281     if (sz == 0)
00282         goto end;
00283 
00284     if (mp->max_codes_bits <= 0)
00285         goto end;
00286     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))
00287         goto end;
00288     mp_decode_frame_helper(mp, &gb);
00289     free_vlc(&mp->vlc);
00290 
00291 end:
00292     *data_size = sizeof(AVFrame);
00293     *(AVFrame *)data = mp->frame;
00294     return buf_size;
00295 }
00296 
00297 static av_cold int mp_decode_end(AVCodecContext *avctx)
00298 {
00299     MotionPixelsContext *mp = avctx->priv_data;
00300 
00301     av_freep(&mp->changes_map);
00302     av_freep(&mp->vpt);
00303     av_freep(&mp->hpt);
00304     av_freep(&mp->bswapbuf);
00305     if (mp->frame.data[0])
00306         avctx->release_buffer(avctx, &mp->frame);
00307 
00308     return 0;
00309 }
00310 
00311 AVCodec ff_motionpixels_decoder = {
00312     .name           = "motionpixels",
00313     .type           = AVMEDIA_TYPE_VIDEO,
00314     .id             = CODEC_ID_MOTIONPIXELS,
00315     .priv_data_size = sizeof(MotionPixelsContext),
00316     .init           = mp_decode_init,
00317     .close          = mp_decode_end,
00318     .decode         = mp_decode_frame,
00319     .capabilities   = CODEC_CAP_DR1,
00320     .long_name = NULL_IF_CONFIG_SMALL("Motion Pixels video"),
00321 };
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