falkTX
/
FFmpeg
mirror of https://github.com/falkTX/FFmpeg.git
1
0
Fork 0
Code Issues 0 Releases 338 Wiki Activity
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
53243 Commits
32 Branches
303MB
Tree: ed0aed09e8
Branches Tags
${ item.name }
Create branch ${ searchTerm }
from 'ed0aed09e8'
${ noResults }
FFmpeg/libavcodec/escape130.c

360 lines
10KB
Raw Blame History 

  1. /*

  2.  * Escape 130 video decoder

  3.  * Copyright (C) 2008 Eli Friedman (eli.friedman <at> gmail.com)

  4.  *

  5.  * This file is part of FFmpeg.

  6.  *

  7.  * FFmpeg is free software; you can redistribute it and/or

  8.  * modify it under the terms of the GNU Lesser General Public

  9.  * License as published by the Free Software Foundation; either

  10.  * version 2.1 of the License, or (at your option) any later version.

  11.  *

  12.  * FFmpeg is distributed in the hope that it will be useful,

  13.  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  14.  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

  15.  * Lesser General Public License for more details.

  16.  *

  17.  * You should have received a copy of the GNU Lesser General Public

  18.  * License along with FFmpeg; if not, write to the Free Software

  19.  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

  20.  */

  21. 

  22. #include "libavutil/attributes.h"

  23. #include "libavutil/mem.h"

  24. #include "avcodec.h"

  25. #define BITSTREAM_READER_LE

  26. #include "get_bits.h"

  27. #include "internal.h"

  28. 

  29. typedef struct Escape130Context {

  30.     uint8_t *old_y_avg;

  31. 

  32.     uint8_t *new_y, *old_y;

  33.     uint8_t *new_u, *old_u;

  34.     uint8_t *new_v, *old_v;

  35. 

  36.     uint8_t *buf1, *buf2;

  37.     int     linesize[3];

  38. } Escape130Context;

  39. 

  40. static const uint8_t offset_table[] = { 2, 4, 10, 20 };

  41. static const int8_t sign_table[64][4] = {

  42.     {  0,  0,  0,  0 },

  43.     { -1,  1,  0,  0 },

  44.     {  1, -1,  0,  0 },

  45.     { -1,  0,  1,  0 },

  46.     { -1,  1,  1,  0 },

  47.     {  0, -1,  1,  0 },

  48.     {  1, -1,  1,  0 },

  49.     { -1, -1,  1,  0 },

  50.     {  1,  0, -1,  0 },

  51.     {  0,  1, -1,  0 },

  52.     {  1,  1, -1,  0 },

  53.     { -1,  1, -1,  0 },

  54.     {  1, -1, -1,  0 },

  55.     { -1,  0,  0,  1 },

  56.     { -1,  1,  0,  1 },

  57.     {  0, -1,  0,  1 },

  58. 

  59.     {  0,  0,  0,  0 },

  60.     {  1, -1,  0,  1 },

  61.     { -1, -1,  0,  1 },

  62.     { -1,  0,  1,  1 },

  63.     { -1,  1,  1,  1 },

  64.     {  0, -1,  1,  1 },

  65.     {  1, -1,  1,  1 },

  66.     { -1, -1,  1,  1 },

  67.     {  0,  0, -1,  1 },

  68.     {  1,  0, -1,  1 },

  69.     { -1,  0, -1,  1 },

  70.     {  0,  1, -1,  1 },

  71.     {  1,  1, -1,  1 },

  72.     { -1,  1, -1,  1 },

  73.     {  0, -1, -1,  1 },

  74.     {  1, -1, -1,  1 },

  75. 

  76.     {  0,  0,  0,  0 },

  77.     { -1, -1, -1,  1 },

  78.     {  1,  0,  0, -1 },

  79.     {  0,  1,  0, -1 },

  80.     {  1,  1,  0, -1 },

  81.     { -1,  1,  0, -1 },

  82.     {  1, -1,  0, -1 },

  83.     {  0,  0,  1, -1 },

  84.     {  1,  0,  1, -1 },

  85.     { -1,  0,  1, -1 },

  86.     {  0,  1,  1, -1 },

  87.     {  1,  1,  1, -1 },

  88.     { -1,  1,  1, -1 },

  89.     {  0, -1,  1, -1 },

  90.     {  1, -1,  1, -1 },

  91.     { -1, -1,  1, -1 },

  92. 

  93.     {  0,  0,  0,  0 },

  94.     {  1,  0, -1, -1 },

  95.     {  0,  1, -1, -1 },

  96.     {  1,  1, -1, -1 },

  97.     { -1,  1, -1, -1 },

  98.     {  1, -1, -1, -1 }

  99. };

  100. 

  101. static const int8_t luma_adjust[] = { -4, -3, -2, -1, 1, 2, 3, 4 };

  102. 

  103. static const int8_t chroma_adjust[2][8] = {

  104.     { 1, 1, 0, -1, -1, -1,  0,  1 },

  105.     { 0, 1, 1,  1,  0, -1, -1, -1 }

  106. };

  107. 

  108. const uint8_t chroma_vals[] = {

  109.      20,  28,  36,  44,  52,  60,  68,  76,

  110.      84,  92, 100, 106, 112, 116, 120, 124,

  111.     128, 132, 136, 140, 144, 150, 156, 164,

  112.     172, 180, 188, 196, 204, 212, 220, 228

  113. };

  114. 

  115. static av_cold int escape130_decode_init(AVCodecContext *avctx)

  116. {

  117.     Escape130Context *s = avctx->priv_data;

  118.     avctx->pix_fmt = AV_PIX_FMT_YUV420P;

  119. 

  120.     if ((avctx->width & 1) || (avctx->height & 1)) {

  121.         av_log(avctx, AV_LOG_ERROR,

  122.                "Dimensions should be a multiple of two.\n");

  123.         return AVERROR_INVALIDDATA;

  124.     }

  125. 

  126.     s->old_y_avg = av_malloc(avctx->width * avctx->height / 4);

  127.     s->buf1      = av_malloc(avctx->width * avctx->height * 3 / 2);

  128.     s->buf2      = av_malloc(avctx->width * avctx->height * 3 / 2);

  129.     if (!s->old_y_avg || !s->buf1 || !s->buf2) {

  130.         av_freep(&s->old_y_avg);

  131.         av_freep(&s->buf1);

  132.         av_freep(&s->buf2);

  133.         av_log(avctx, AV_LOG_ERROR, "Could not allocate buffer.\n");

  134.         return AVERROR(ENOMEM);

  135.     }

  136. 

  137.     s->linesize[0] = avctx->width;

  138.     s->linesize[1] =

  139.     s->linesize[2] = avctx->width / 2;

  140. 

  141.     s->new_y = s->buf1;

  142.     s->new_u = s->new_y + avctx->width * avctx->height;

  143.     s->new_v = s->new_u + avctx->width * avctx->height / 4;

  144.     s->old_y = s->buf2;

  145.     s->old_u = s->old_y + avctx->width * avctx->height;

  146.     s->old_v = s->old_u + avctx->width * avctx->height / 4;

  147.     memset(s->old_y, 0,    avctx->width * avctx->height);

  148.     memset(s->old_u, 0x10, avctx->width * avctx->height / 4);

  149.     memset(s->old_v, 0x10, avctx->width * avctx->height / 4);

  150. 

  151.     return 0;

  152. }

  153. 

  154. static av_cold int escape130_decode_close(AVCodecContext *avctx)

  155. {

  156.     Escape130Context *s = avctx->priv_data;

  157. 

  158.     av_freep(&s->old_y_avg);

  159.     av_freep(&s->buf1);

  160.     av_freep(&s->buf2);

  161. 

  162.     return 0;

  163. }

  164. 

  165. static int decode_skip_count(GetBitContext* gb)

  166. {

  167.     int value;

  168. 

  169.     if (get_bits_left(gb) < 1+3)

  170.         return -1;

  171. 

  172.     value = get_bits1(gb);

  173.     if (value)

  174.         return 0;

  175. 

  176.     value = get_bits(gb, 3);

  177.     if (value)

  178.         return value;

  179. 

  180.     value = get_bits(gb, 8);

  181.     if (value)

  182.         return value + 7;

  183. 

  184.     value = get_bits(gb, 15);

  185.     if (value)

  186.         return value + 262;

  187. 

  188.     return -1;

  189. }

  190. 

  191. static int escape130_decode_frame(AVCodecContext *avctx, void *data,

  192.                                   int *got_frame, AVPacket *avpkt)

  193. {

  194.     const uint8_t *buf  = avpkt->data;

  195.     int buf_size        = avpkt->size;

  196.     Escape130Context *s = avctx->priv_data;

  197.     AVFrame *pic        = data;

  198.     GetBitContext gb;

  199.     int ret;

  200. 

  201.     uint8_t *old_y, *old_cb, *old_cr,

  202.             *new_y, *new_cb, *new_cr;

  203.     uint8_t *dstY, *dstU, *dstV;

  204.     unsigned old_y_stride, old_cb_stride, old_cr_stride,

  205.              new_y_stride, new_cb_stride, new_cr_stride;

  206.     unsigned total_blocks = avctx->width * avctx->height / 4,

  207.              block_index, block_x = 0;

  208.     unsigned y[4] = { 0 }, cb = 0x10, cr = 0x10;

  209.     int skip = -1, y_avg = 0, i, j;

  210.     uint8_t *ya = s->old_y_avg;

  211. 

  212.     // first 16 bytes are header; no useful information in here

  213.     if (buf_size <= 16) {

  214.         av_log(avctx, AV_LOG_ERROR, "Insufficient frame data\n");

  215.         return AVERROR_INVALIDDATA;

  216.     }

  217. 

  218.     if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)

  219.         return ret;

  220. 

  221.     init_get_bits(&gb, buf + 16, (buf_size - 16) * 8);

  222. 

  223.     new_y  = s->new_y;

  224.     new_cb = s->new_u;

  225.     new_cr = s->new_v;

  226.     new_y_stride  = s->linesize[0];

  227.     new_cb_stride = s->linesize[1];

  228.     new_cr_stride = s->linesize[2];

  229.     old_y  = s->old_y;

  230.     old_cb = s->old_u;

  231.     old_cr = s->old_v;

  232.     old_y_stride  = s->linesize[0];

  233.     old_cb_stride = s->linesize[1];

  234.     old_cr_stride = s->linesize[2];

  235. 

  236.     for (block_index = 0; block_index < total_blocks; block_index++) {

  237.         // Note that this call will make us skip the rest of the blocks

  238.         // if the frame ends prematurely.

  239.         if (skip == -1)

  240.             skip = decode_skip_count(&gb);

  241.         if (skip == -1) {

  242.             av_log(avctx, AV_LOG_ERROR, "Error decoding skip value\n");

  243.             return AVERROR_INVALIDDATA;

  244.         }

  245. 

  246.         if (skip) {

  247.             y[0] = old_y[0];

  248.             y[1] = old_y[1];

  249.             y[2] = old_y[old_y_stride];

  250.             y[3] = old_y[old_y_stride + 1];

  251.             y_avg = ya[0];

  252.             cb = old_cb[0];

  253.             cr = old_cr[0];

  254.         } else {

  255.             if (get_bits1(&gb)) {

  256.                 unsigned sign_selector       = get_bits(&gb, 6);

  257.                 unsigned difference_selector = get_bits(&gb, 2);

  258.                 y_avg = 2 * get_bits(&gb, 5);

  259.                 for (i = 0; i < 4; i++) {

  260.                     y[i] = av_clip(y_avg + offset_table[difference_selector] *

  261.                                    sign_table[sign_selector][i], 0, 63);

  262.                 }

  263.             } else if (get_bits1(&gb)) {

  264.                 if (get_bits1(&gb)) {

  265.                     y_avg = get_bits(&gb, 6);

  266.                 } else {

  267.                     unsigned adjust_index = get_bits(&gb, 3);

  268.                     y_avg = (y_avg + luma_adjust[adjust_index]) & 63;

  269.                 }

  270.                 for (i = 0; i < 4; i++)

  271.                     y[i] = y_avg;

  272.             }

  273. 

  274.             if (get_bits1(&gb)) {

  275.                 if (get_bits1(&gb)) {

  276.                     cb = get_bits(&gb, 5);

  277.                     cr = get_bits(&gb, 5);

  278.                 } else {

  279.                     unsigned adjust_index = get_bits(&gb, 3);

  280.                     cb = (cb + chroma_adjust[0][adjust_index]) & 31;

  281.                     cr = (cr + chroma_adjust[1][adjust_index]) & 31;

  282.                 }

  283.             }

  284.         }

  285.         *ya++ = y_avg;

  286. 

  287.         new_y[0]                = y[0];

  288.         new_y[1]                = y[1];

  289.         new_y[new_y_stride]     = y[2];

  290.         new_y[new_y_stride + 1] = y[3];

  291.         *new_cb = cb;

  292.         *new_cr = cr;

  293. 

  294.         old_y += 2;

  295.         old_cb++;

  296.         old_cr++;

  297.         new_y += 2;

  298.         new_cb++;

  299.         new_cr++;

  300.         block_x++;

  301.         if (block_x * 2 == avctx->width) {

  302.             block_x = 0;

  303.             old_y  += old_y_stride * 2  - avctx->width;

  304.             old_cb += old_cb_stride     - avctx->width / 2;

  305.             old_cr += old_cr_stride     - avctx->width / 2;

  306.             new_y  += new_y_stride * 2  - avctx->width;

  307.             new_cb += new_cb_stride     - avctx->width / 2;

  308.             new_cr += new_cr_stride     - avctx->width / 2;

  309.         }

  310. 

  311.         skip--;

  312.     }

  313. 

  314.     new_y  = s->new_y;

  315.     new_cb = s->new_u;

  316.     new_cr = s->new_v;

  317.     dstY   = pic->data[0];

  318.     dstU   = pic->data[1];

  319.     dstV   = pic->data[2];

  320.     for (j = 0; j < avctx->height; j++) {

  321.         for (i = 0; i < avctx->width; i++)

  322.             dstY[i] = new_y[i] << 2;

  323.         dstY  += pic->linesize[0];

  324.         new_y += new_y_stride;

  325.     }

  326.     for (j = 0; j < avctx->height / 2; j++) {

  327.         for (i = 0; i < avctx->width / 2; i++) {

  328.             dstU[i] = chroma_vals[new_cb[i]];

  329.             dstV[i] = chroma_vals[new_cr[i]];

  330.         }

  331.         dstU   += pic->linesize[1];

  332.         dstV   += pic->linesize[2];

  333.         new_cb += new_cb_stride;

  334.         new_cr += new_cr_stride;

  335.     }

  336. 

  337.     av_dlog(avctx, "Frame data: provided %d bytes, used %d bytes\n",

  338.             buf_size, get_bits_count(&gb) >> 3);

  339. 

  340.     FFSWAP(uint8_t*, s->old_y, s->new_y);

  341.     FFSWAP(uint8_t*, s->old_u, s->new_u);

  342.     FFSWAP(uint8_t*, s->old_v, s->new_v);

  343. 

  344.     *got_frame = 1;

  345. 

  346.     return buf_size;

  347. }

  348. 

  349. AVCodec ff_escape130_decoder = {

  350.     .name           = "escape130",

  351.     .type           = AVMEDIA_TYPE_VIDEO,

  352.     .id             = AV_CODEC_ID_ESCAPE130,

  353.     .priv_data_size = sizeof(Escape130Context),

  354.     .init           = escape130_decode_init,

  355.     .close          = escape130_decode_close,

  356.     .decode         = escape130_decode_frame,

  357.     .capabilities   = CODEC_CAP_DR1,

  358.     .long_name      = NULL_IF_CONFIG_SMALL("Escape 130"),

  359. };