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 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     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     avcodec_get_frame_defaults(&mp->frame);
00067     return 0;
00068 }
00069 
00070 static void mp_read_changes_map(MotionPixelsContext *mp, GetBitContext *gb, int count, int bits_len, int read_color)
00071 {
00072     uint16_t *pixels;
00073     int offset, w, h, color = 0, x, y, i;
00074 
00075     while (count--) {
00076         offset = get_bits_long(gb, mp->offset_bits_len);
00077         w      = get_bits(gb, bits_len) + 1;
00078         h      = get_bits(gb, bits_len) + 1;
00079         if (read_color)
00080             color = get_bits(gb, 15);
00081         x = offset % mp->avctx->width;
00082         y = offset / mp->avctx->width;
00083         if (y >= mp->avctx->height)
00084             continue;
00085         w = FFMIN(w, mp->avctx->width  - x);
00086         h = FFMIN(h, mp->avctx->height - y);
00087         pixels = (uint16_t *)&mp->frame.data[0][y * mp->frame.linesize[0] + x * 2];
00088         while (h--) {
00089             mp->changes_map[offset] = w;
00090             if (read_color)
00091                 for (i = 0; i < w; ++i)
00092                     pixels[i] = color;
00093             offset += mp->avctx->width;
00094             pixels += mp->frame.linesize[0] / 2;
00095         }
00096     }
00097 }
00098 
00099 static void mp_get_code(MotionPixelsContext *mp, GetBitContext *gb, int size, int code)
00100 {
00101     while (get_bits1(gb)) {
00102         ++size;
00103         if (size > mp->max_codes_bits) {
00104             av_log(mp->avctx, AV_LOG_ERROR, "invalid code size %d/%d\n", size, mp->max_codes_bits);
00105             return;
00106         }
00107         code <<= 1;
00108         mp_get_code(mp, gb, size, code + 1);
00109     }
00110     if (mp->current_codes_count >= MAX_HUFF_CODES) {
00111         av_log(mp->avctx, AV_LOG_ERROR, "too many codes\n");
00112         return;
00113     }
00114     mp->codes[mp->current_codes_count  ].code = code;
00115     mp->codes[mp->current_codes_count++].size = size;
00116 }
00117 
00118 static void mp_read_codes_table(MotionPixelsContext *mp, GetBitContext *gb)
00119 {
00120     if (mp->codes_count == 1) {
00121         mp->codes[0].delta = get_bits(gb, 4);
00122     } else {
00123         int i;
00124 
00125         mp->max_codes_bits = get_bits(gb, 4);
00126         for (i = 0; i < mp->codes_count; ++i)
00127             mp->codes[i].delta = get_bits(gb, 4);
00128         mp->current_codes_count = 0;
00129         mp_get_code(mp, gb, 0, 0);
00130    }
00131 }
00132 
00133 static int mp_gradient(MotionPixelsContext *mp, int component, int v)
00134 {
00135     int delta;
00136 
00137     delta = (v - 7) * mp->gradient_scale[component];
00138     mp->gradient_scale[component] = (v == 0 || v == 14) ? 2 : 1;
00139     return delta;
00140 }
00141 
00142 static YuvPixel mp_get_yuv_from_rgb(MotionPixelsContext *mp, int x, int y)
00143 {
00144     int color;
00145 
00146     color = *(uint16_t *)&mp->frame.data[0][y * mp->frame.linesize[0] + x * 2];
00147     return mp_rgb_yuv_table[color];
00148 }
00149 
00150 static void mp_set_rgb_from_yuv(MotionPixelsContext *mp, int x, int y, const YuvPixel *p)
00151 {
00152     int color;
00153 
00154     color = mp_yuv_to_rgb(p->y, p->v, p->u, 1);
00155     *(uint16_t *)&mp->frame.data[0][y * mp->frame.linesize[0] + x * 2] = color;
00156 }
00157 
00158 static int mp_get_vlc(MotionPixelsContext *mp, GetBitContext *gb)
00159 {
00160     int i;
00161 
00162     i = (mp->codes_count == 1) ? 0 : get_vlc2(gb, mp->vlc.table, mp->max_codes_bits, 1);
00163     return mp->codes[i].delta;
00164 }
00165 
00166 static void mp_decode_line(MotionPixelsContext *mp, GetBitContext *gb, int y)
00167 {
00168     YuvPixel p;
00169     const int y0 = y * mp->avctx->width;
00170     int w, i, x = 0;
00171 
00172     p = mp->vpt[y];
00173     if (mp->changes_map[y0 + x] == 0) {
00174         memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));
00175         ++x;
00176     }
00177     while (x < mp->avctx->width) {
00178         w = mp->changes_map[y0 + x];
00179         if (w != 0) {
00180             if ((y & 3) == 0) {
00181                 if (mp->changes_map[y0 + x + mp->avctx->width] < w ||
00182                     mp->changes_map[y0 + x + mp->avctx->width * 2] < w ||
00183                     mp->changes_map[y0 + x + mp->avctx->width * 3] < w) {
00184                     for (i = (x + 3) & ~3; i < x + w; i += 4) {
00185                         mp->hpt[((y / 4) * mp->avctx->width + i) / 4] = mp_get_yuv_from_rgb(mp, i, y);
00186                     }
00187                 }
00188             }
00189             x += w;
00190             memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));
00191             p = mp_get_yuv_from_rgb(mp, x - 1, y);
00192         } else {
00193             p.y += mp_gradient(mp, 0, mp_get_vlc(mp, gb));
00194             p.y = av_clip(p.y, 0, 31);
00195             if ((x & 3) == 0) {
00196                 if ((y & 3) == 0) {
00197                     p.v += mp_gradient(mp, 1, mp_get_vlc(mp, gb));
00198                     p.v = av_clip(p.v, -32, 31);
00199                     p.u += mp_gradient(mp, 2, mp_get_vlc(mp, gb));
00200                     p.u = av_clip(p.u, -32, 31);
00201                     mp->hpt[((y / 4) * mp->avctx->width + x) / 4] = p;
00202                 } else {
00203                     p.v = mp->hpt[((y / 4) * mp->avctx->width + x) / 4].v;
00204                     p.u = mp->hpt[((y / 4) * mp->avctx->width + x) / 4].u;
00205                 }
00206             }
00207             mp_set_rgb_from_yuv(mp, x, y, &p);
00208             ++x;
00209         }
00210     }
00211 }
00212 
00213 static void mp_decode_frame_helper(MotionPixelsContext *mp, GetBitContext *gb)
00214 {
00215     YuvPixel p;
00216     int y, y0;
00217 
00218     for (y = 0; y < mp->avctx->height; ++y) {
00219         if (mp->changes_map[y * mp->avctx->width] != 0) {
00220             memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));
00221             p = mp_get_yuv_from_rgb(mp, 0, y);
00222         } else {
00223             p.y += mp_gradient(mp, 0, mp_get_vlc(mp, gb));
00224             p.y = av_clip(p.y, 0, 31);
00225             if ((y & 3) == 0) {
00226                 p.v += mp_gradient(mp, 1, mp_get_vlc(mp, gb));
00227                 p.v = av_clip(p.v, -32, 31);
00228                 p.u += mp_gradient(mp, 2, mp_get_vlc(mp, gb));
00229                 p.u = av_clip(p.u, -32, 31);
00230             }
00231             mp->vpt[y] = p;
00232             mp_set_rgb_from_yuv(mp, 0, y, &p);
00233         }
00234     }
00235     for (y0 = 0; y0 < 2; ++y0)
00236         for (y = y0; y < mp->avctx->height; y += 2)
00237             mp_decode_line(mp, gb, y);
00238 }
00239 
00240 static int mp_decode_frame(AVCodecContext *avctx,
00241                                  void *data, int *data_size,
00242                                  AVPacket *avpkt)
00243 {
00244     const uint8_t *buf = avpkt->data;
00245     int buf_size = avpkt->size;
00246     MotionPixelsContext *mp = avctx->priv_data;
00247     GetBitContext gb;
00248     int i, count1, count2, sz;
00249 
00250     mp->frame.reference = 3;
00251     mp->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
00252     if (avctx->reget_buffer(avctx, &mp->frame)) {
00253         av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
00254         return -1;
00255     }
00256 
00257     /* le32 bitstream msb first */
00258     av_fast_malloc(&mp->bswapbuf, &mp->bswapbuf_size, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
00259     if (!mp->bswapbuf)
00260         return AVERROR(ENOMEM);
00261     mp->dsp.bswap_buf((uint32_t *)mp->bswapbuf, (const uint32_t *)buf, buf_size / 4);
00262     if (buf_size & 3)
00263         memcpy(mp->bswapbuf + (buf_size & ~3), buf + (buf_size & ~3), buf_size & 3);
00264     memset(mp->bswapbuf + buf_size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
00265     init_get_bits(&gb, mp->bswapbuf, buf_size * 8);
00266 
00267     memset(mp->changes_map, 0, avctx->width * avctx->height);
00268     for (i = !(avctx->extradata[1] & 2); i < 2; ++i) {
00269         count1 = get_bits(&gb, 12);
00270         count2 = get_bits(&gb, 12);
00271         mp_read_changes_map(mp, &gb, count1, 8, i);
00272         mp_read_changes_map(mp, &gb, count2, 4, i);
00273     }
00274 
00275     mp->codes_count = get_bits(&gb, 4);
00276     if (mp->codes_count == 0)
00277         goto end;
00278 
00279     if (mp->changes_map[0] == 0) {
00280         *(uint16_t *)mp->frame.data[0] = get_bits(&gb, 15);
00281         mp->changes_map[0] = 1;
00282     }
00283     mp_read_codes_table(mp, &gb);
00284 
00285     sz = get_bits(&gb, 18);
00286     if (avctx->extradata[0] != 5)
00287         sz += get_bits(&gb, 18);
00288     if (sz == 0)
00289         goto end;
00290 
00291     if (mp->max_codes_bits <= 0)
00292         goto end;
00293     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))
00294         goto end;
00295     mp_decode_frame_helper(mp, &gb);
00296     free_vlc(&mp->vlc);
00297 
00298 end:
00299     *data_size = sizeof(AVFrame);
00300     *(AVFrame *)data = mp->frame;
00301     return buf_size;
00302 }
00303 
00304 static av_cold int mp_decode_end(AVCodecContext *avctx)
00305 {
00306     MotionPixelsContext *mp = avctx->priv_data;
00307 
00308     av_freep(&mp->changes_map);
00309     av_freep(&mp->vpt);
00310     av_freep(&mp->hpt);
00311     av_freep(&mp->bswapbuf);
00312     if (mp->frame.data[0])
00313         avctx->release_buffer(avctx, &mp->frame);
00314 
00315     return 0;
00316 }
00317 
00318 AVCodec ff_motionpixels_decoder = {
00319     .name           = "motionpixels",
00320     .type           = AVMEDIA_TYPE_VIDEO,
00321     .id             = CODEC_ID_MOTIONPIXELS,
00322     .priv_data_size = sizeof(MotionPixelsContext),
00323     .init           = mp_decode_init,
00324     .close          = mp_decode_end,
00325     .decode         = mp_decode_frame,
00326     .capabilities   = CODEC_CAP_DR1,
00327     .long_name = NULL_IF_CONFIG_SMALL("Motion Pixels video"),
00328 };