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FFmpeg/libavcodec/dv.c

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  1. /*

  2.  * DV decoder

  3.  * Copyright (c) 2002 Fabrice Bellard.

  4.  *

  5.  * DV encoder 

  6.  * Copyright (c) 2003 Roman Shaposhnik.

  7.  *

  8.  * Many thanks to Dan Dennedy <dan@dennedy.org> for providing wealth

  9.  * of DV technical info.

  10.  *

  11.  * This library is free software; you can redistribute it and/or

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

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

  14.  * version 2 of the License, or (at your option) any later version.

  15.  *

  16.  * This library is distributed in the hope that it will be useful,

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

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

  19.  * Lesser General Public License for more details.

  20.  *

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

  22.  * License along with this library; if not, write to the Free Software

  23.  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

  24.  */

  25. 

  26. /**

  27.  * @file dv.c

  28.  * DV codec.

  29.  */

  30. #include "avcodec.h"

  31. #include "dsputil.h"

  32. #include "mpegvideo.h"

  33. #include "simple_idct.h"

  34. #include "dvdata.h"

  35. 

  36. typedef struct DVVideoDecodeContext {

  37.     const DVprofile* sys;

  38.     AVFrame picture;

  39.     

  40.     uint8_t dv_zigzag[2][64];

  41.     uint8_t dv_idct_shift[2][22][64];

  42.     uint8_t dv_dct_shift[2][22][64];

  43.   

  44.     void (*get_pixels)(DCTELEM *block, const uint8_t *pixels, int line_size);

  45.     void (*fdct[2])(DCTELEM *block);

  46.     void (*idct_put[2])(uint8_t *dest, int line_size, DCTELEM *block);

  47.     

  48.     GetBitContext gb;

  49.     DCTELEM block[5*6][64] __align8;

  50. } DVVideoDecodeContext;

  51. 

  52. #define TEX_VLC_BITS 9

  53. /* XXX: also include quantization */

  54. static RL_VLC_ELEM *dv_rl_vlc[1];

  55. static VLC_TYPE dv_vlc_codes[15][23];

  56. 

  57. static void dv_build_unquantize_tables(DVVideoDecodeContext *s, uint8_t* perm)

  58. {

  59.     int i, q, j;

  60. 

  61.     /* NOTE: max left shift is 6 */

  62.     for(q = 0; q < 22; q++) {

  63.         /* 88DCT */

  64.         for(i = 1; i < 64; i++) {

  65.             /* 88 table */

  66.             j = perm[i];

  67.             s->dv_idct_shift[0][q][j] =

  68.                 dv_quant_shifts[q][dv_88_areas[i]] + 1;

  69.             s->dv_dct_shift[0][q][i] =

  70.                 dv_quant_shifts[q][dv_88_areas[ff_zigzag_direct[i]]] + 4;

  71.         }

  72.         

  73.         /* 248DCT */

  74.         for(i = 1; i < 64; i++) {

  75.             /* 248 table */

  76.             s->dv_idct_shift[1][q][i] =  

  77.                 dv_quant_shifts[q][dv_248_areas[i]] + 1;

  78. 	    s->dv_dct_shift[1][q][i] =  

  79.                 dv_quant_shifts[q][dv_248_areas[ff_zigzag248_direct[i]]] + 4;

  80.         }

  81.     }

  82. }

  83. 

  84. static int dvvideo_init(AVCodecContext *avctx)

  85. {

  86.     DVVideoDecodeContext *s = avctx->priv_data;

  87.     DSPContext dsp;

  88.     static int done=0;

  89.     int i;

  90. 

  91.     if (!done) {

  92.         int i;

  93.         VLC dv_vlc;

  94. 

  95.         done = 1;

  96. 

  97.         /* NOTE: as a trick, we use the fact the no codes are unused

  98.            to accelerate the parsing of partial codes */

  99.         init_vlc(&dv_vlc, TEX_VLC_BITS, NB_DV_VLC, 

  100.                  dv_vlc_len, 1, 1, dv_vlc_bits, 2, 2);

  101. 

  102.         dv_rl_vlc[0] = av_malloc(dv_vlc.table_size * sizeof(RL_VLC_ELEM));

  103.         for(i = 0; i < dv_vlc.table_size; i++){

  104.             int code= dv_vlc.table[i][0];

  105.             int len = dv_vlc.table[i][1];

  106.             int level, run;

  107.         

  108.             if(len<0){ //more bits needed

  109.                 run= 0;

  110.                 level= code;

  111.             } else if (code == (NB_DV_VLC - 1)) {

  112.                 /* EOB */

  113.                 run = 0;

  114.                 level = 256;

  115.             } else {

  116.                 run=   dv_vlc_run[code] + 1;

  117.                 level= dv_vlc_level[code];

  118.             }

  119.             dv_rl_vlc[0][i].len = len;

  120.             dv_rl_vlc[0][i].level = level;

  121.             dv_rl_vlc[0][i].run = run;

  122.         }

  123. 

  124. 	memset(dv_vlc_codes, 0xff, sizeof(dv_vlc_codes));

  125. 	for (i = 0; i < NB_DV_VLC - 1; i++) {

  126. 	   if (dv_vlc_run[i] < 15 && dv_vlc_level[i] < 23 && dv_vlc_len[i] < 15)

  127. 	       dv_vlc_codes[dv_vlc_run[i]][dv_vlc_level[i]] = i;

  128. 	}

  129.     }

  130. 

  131.     /* Generic DSP setup */

  132.     dsputil_init(&dsp, avctx);

  133.     s->get_pixels = dsp.get_pixels;

  134. 

  135.     /* 88DCT setup */

  136.     s->fdct[0] = dsp.fdct;

  137.     s->idct_put[0] = dsp.idct_put;

  138.     for (i=0; i<64; i++)

  139.        s->dv_zigzag[0][i] = dsp.idct_permutation[ff_zigzag_direct[i]];

  140. 

  141.     /* 248DCT setup */

  142.     s->fdct[1] = dsp.fdct248;

  143.     s->idct_put[1] = simple_idct248_put;  // FIXME: need to add it to DSP

  144.     memcpy(s->dv_zigzag[1], ff_zigzag248_direct, 64);

  145. 

  146.     /* XXX: do it only for constant case */

  147.     dv_build_unquantize_tables(s, dsp.idct_permutation);

  148. 

  149.     /* FIXME: I really don't think this should be here */

  150.     if (dv_codec_profile(avctx))

  151. 	avctx->pix_fmt = dv_codec_profile(avctx)->pix_fmt; 

  152.     avctx->coded_frame = &s->picture;

  153.     

  154.     return 0;

  155. }

  156. 

  157. // #define VLC_DEBUG

  158. 

  159. typedef struct BlockInfo {

  160.     const uint8_t *shift_table;

  161.     const uint8_t *scan_table;

  162.     uint8_t pos; /* position in block */

  163.     uint8_t eob_reached; /* true if EOB has been reached */

  164.     uint8_t dct_mode;

  165.     uint8_t partial_bit_count;

  166.     uint16_t partial_bit_buffer;

  167.     int shift_offset;

  168. } BlockInfo;

  169. 

  170. /* block size in bits */

  171. static const uint16_t block_sizes[6] = {

  172.     112, 112, 112, 112, 80, 80

  173. };

  174. 

  175. #ifndef ALT_BITSTREAM_READER

  176. #warning only works with ALT_BITSTREAM_READER

  177. #endif

  178. 

  179. /* decode ac coefs */

  180. static void dv_decode_ac(DVVideoDecodeContext *s, 

  181.                          BlockInfo *mb, DCTELEM *block, int last_index)

  182. {

  183.     int last_re_index;

  184.     int shift_offset = mb->shift_offset;

  185.     const uint8_t *scan_table = mb->scan_table;

  186.     const uint8_t *shift_table = mb->shift_table;

  187.     int pos = mb->pos;

  188.     int level, pos1, sign, run;

  189.     int partial_bit_count;

  190. #ifndef ALT_BITSTREAM_READER //FIXME

  191.     int re_index=0; 

  192.     int re1_index=0;

  193. #endif

  194.     OPEN_READER(re, &s->gb);

  195.     

  196. #ifdef VLC_DEBUG

  197.     printf("start\n");

  198. #endif

  199. 

  200.     /* if we must parse a partial vlc, we do it here */

  201.     partial_bit_count = mb->partial_bit_count;

  202.     if (partial_bit_count > 0) {

  203.         uint8_t buf[4];

  204.         uint32_t v;

  205.         int l, l1;

  206.         GetBitContext gb1;

  207. 

  208.         /* build the dummy bit buffer */

  209.         l = 16 - partial_bit_count;

  210.         UPDATE_CACHE(re, &s->gb);

  211. #ifdef VLC_DEBUG

  212.         printf("show=%04x\n", SHOW_UBITS(re, &s->gb, 16));

  213. #endif

  214.         v = (mb->partial_bit_buffer << l) | SHOW_UBITS(re, &s->gb, l);

  215.         buf[0] = v >> 8;

  216.         buf[1] = v;

  217. #ifdef VLC_DEBUG

  218.         printf("v=%04x cnt=%d %04x\n", 

  219.                v, partial_bit_count, (mb->partial_bit_buffer << l));

  220. #endif

  221.         /* try to read the codeword */

  222.         init_get_bits(&gb1, buf, 4*8);

  223.         {

  224.             OPEN_READER(re1, &gb1);

  225.             UPDATE_CACHE(re1, &gb1);

  226.             GET_RL_VLC(level, run, re1, &gb1, dv_rl_vlc[0], 

  227.                        TEX_VLC_BITS, 2);

  228.             l = re1_index;

  229.             CLOSE_READER(re1, &gb1);

  230.         }

  231. #ifdef VLC_DEBUG

  232.         printf("****run=%d level=%d size=%d\n", run, level, l);

  233. #endif

  234.         /* compute codeword length */

  235.         l1 = (level != 256 && level != 0);

  236.         /* if too long, we cannot parse */

  237.         l -= partial_bit_count;

  238.         if ((re_index + l + l1) > last_index)

  239.             return;

  240.         /* skip read bits */

  241.         last_re_index = 0; /* avoid warning */

  242.         re_index += l;

  243.         /* by definition, if we can read the vlc, all partial bits

  244.            will be read (otherwise we could have read the vlc before) */

  245.         mb->partial_bit_count = 0;

  246.         UPDATE_CACHE(re, &s->gb);

  247.         goto handle_vlc;

  248.     }

  249. 

  250.     /* get the AC coefficients until last_index is reached */

  251.     for(;;) {

  252.         UPDATE_CACHE(re, &s->gb);

  253. #ifdef VLC_DEBUG

  254.         printf("%2d: bits=%04x index=%d\n", 

  255.                pos, SHOW_UBITS(re, &s->gb, 16), re_index);

  256. #endif

  257.         last_re_index = re_index;

  258.         GET_RL_VLC(level, run, re, &s->gb, dv_rl_vlc[0], 

  259.                    TEX_VLC_BITS, 2);

  260.     handle_vlc:

  261. #ifdef VLC_DEBUG

  262.         printf("run=%d level=%d\n", run, level);

  263. #endif

  264.         if (level == 256) {

  265.             if (re_index > last_index) {

  266.             cannot_read:

  267.                 /* put position before read code */

  268.                 re_index = last_re_index;

  269.                 mb->eob_reached = 0;

  270.                 break;

  271.             }

  272.             /* EOB */

  273.             mb->eob_reached = 1;

  274.             break;

  275.         } else if (level != 0) {

  276.             if ((re_index + 1) > last_index)

  277.                 goto cannot_read;

  278.             sign = SHOW_SBITS(re, &s->gb, 1);

  279.             level = (level ^ sign) - sign;

  280.             LAST_SKIP_BITS(re, &s->gb, 1);

  281.             pos += run;

  282.             /* error */

  283.             if (pos >= 64) {

  284.                 goto read_error;

  285.             }

  286.             pos1 = scan_table[pos];

  287.             level = level << (shift_table[pos1] + shift_offset);

  288.             block[pos1] = level;

  289.             //            printf("run=%d level=%d shift=%d\n", run, level, shift_table[pos1]);

  290.         } else {

  291.             if (re_index > last_index)

  292.                 goto cannot_read;

  293.             /* level is zero: means run without coding. No

  294.                sign is coded */

  295.             pos += run;

  296.             /* error */

  297.             if (pos >= 64) {

  298.             read_error:

  299. #if defined(VLC_DEBUG) || 1

  300.                 av_log(NULL, AV_LOG_ERROR, "error pos=%d\n", pos);

  301. #endif

  302.                 /* for errors, we consider the eob is reached */

  303.                 mb->eob_reached = 1;

  304.                 break;

  305.             }

  306.         }

  307.     }

  308.     CLOSE_READER(re, &s->gb);

  309.     mb->pos = pos;

  310. }

  311. 

  312. static inline void bit_copy(PutBitContext *pb, GetBitContext *gb, int bits_left)

  313. {

  314.     while (bits_left >= 16) {

  315.         put_bits(pb, 16, get_bits(gb, 16));

  316.         bits_left -= 16;

  317.     }

  318.     if (bits_left > 0) {

  319.         put_bits(pb, bits_left, get_bits(gb, bits_left));

  320.     }

  321. }

  322. 

  323. /* mb_x and mb_y are in units of 8 pixels */

  324. static inline void dv_decode_video_segment(DVVideoDecodeContext *s, 

  325.                                            uint8_t *buf_ptr1, 

  326.                                            const uint16_t *mb_pos_ptr)

  327. {

  328.     int quant, dc, dct_mode, class1, j;

  329.     int mb_index, mb_x, mb_y, v, last_index;

  330.     DCTELEM *block, *block1;

  331.     int c_offset, bits_left;

  332.     uint8_t *y_ptr;

  333.     BlockInfo mb_data[5 * 6], *mb, *mb1;

  334.     void (*idct_put)(uint8_t *dest, int line_size, DCTELEM *block);

  335.     uint8_t *buf_ptr;

  336.     PutBitContext pb, vs_pb;

  337.     uint8_t mb_bit_buffer[80 + 4]; /* allow some slack */

  338.     int mb_bit_count;

  339.     uint8_t vs_bit_buffer[5 * 80 + 4]; /* allow some slack */

  340.     int vs_bit_count;

  341.     

  342.     memset(s->block, 0, sizeof(s->block));

  343. 

  344.     /* pass 1 : read DC and AC coefficients in blocks */

  345.     buf_ptr = buf_ptr1;

  346.     block1 = &s->block[0][0];

  347.     mb1 = mb_data;

  348.     init_put_bits(&vs_pb, vs_bit_buffer, 5 * 80);

  349.     vs_bit_count = 0;

  350.     for(mb_index = 0; mb_index < 5; mb_index++) {

  351.         /* skip header */

  352.         quant = buf_ptr[3] & 0x0f;

  353.         buf_ptr += 4;

  354.         init_put_bits(&pb, mb_bit_buffer, 80);

  355.         mb_bit_count = 0;

  356.         mb = mb1;

  357.         block = block1;

  358.         for(j = 0;j < 6; j++) {

  359.             /* NOTE: size is not important here */

  360.             init_get_bits(&s->gb, buf_ptr, 14*8);

  361.             

  362.             /* get the dc */

  363.             dc = get_bits(&s->gb, 9);

  364.             dc = (dc << (32 - 9)) >> (32 - 9);

  365.             dct_mode = get_bits1(&s->gb);

  366.             mb->dct_mode = dct_mode;

  367.             mb->scan_table = s->dv_zigzag[dct_mode];

  368.             class1 = get_bits(&s->gb, 2);

  369.             mb->shift_offset = (class1 == 3);

  370.             mb->shift_table = s->dv_idct_shift[dct_mode]

  371.                 [quant + dv_quant_offset[class1]];

  372.             dc = dc << 2;

  373.             /* convert to unsigned because 128 is not added in the

  374.                standard IDCT */

  375.             dc += 1024;

  376.             block[0] = dc;

  377.             last_index = block_sizes[j];

  378.             buf_ptr += last_index >> 3;

  379.             mb->pos = 0;

  380.             mb->partial_bit_count = 0;

  381. 

  382. #ifdef VLC_DEBUG

  383.             printf("MB block: %d, %d ", mb_index, j);

  384. #endif

  385.             dv_decode_ac(s, mb, block, last_index);

  386. 

  387.             /* write the remaining bits  in a new buffer only if the

  388.                block is finished */

  389.             bits_left = last_index - get_bits_count(&s->gb);

  390.             if (mb->eob_reached) {

  391.                 mb->partial_bit_count = 0;

  392.                 mb_bit_count += bits_left;

  393.                 bit_copy(&pb, &s->gb, bits_left);

  394.             } else {

  395.                 /* should be < 16 bits otherwise a codeword could have

  396.                    been parsed */

  397.                 mb->partial_bit_count = bits_left;

  398.                 mb->partial_bit_buffer = get_bits(&s->gb, bits_left);

  399.             }

  400.             block += 64;

  401.             mb++;

  402.         }

  403.         

  404.         flush_put_bits(&pb);

  405. 

  406.         /* pass 2 : we can do it just after */

  407. #ifdef VLC_DEBUG

  408.         printf("***pass 2 size=%d MB#=%d\n", mb_bit_count, mb_index);

  409. #endif

  410.         block = block1;

  411.         mb = mb1;

  412.         init_get_bits(&s->gb, mb_bit_buffer, 80*8);

  413.         for(j = 0;j < 6; j++) {

  414.             if (!mb->eob_reached && get_bits_count(&s->gb) < mb_bit_count) {

  415.                 dv_decode_ac(s, mb, block, mb_bit_count);

  416.                 /* if still not finished, no need to parse other blocks */

  417.                 if (!mb->eob_reached) {

  418.                     /* we could not parse the current AC coefficient,

  419.                        so we add the remaining bytes */

  420.                     bits_left = mb_bit_count - get_bits_count(&s->gb);

  421.                     if (bits_left > 0) {

  422.                         mb->partial_bit_count += bits_left;

  423.                         mb->partial_bit_buffer = 

  424.                             (mb->partial_bit_buffer << bits_left) | 

  425.                             get_bits(&s->gb, bits_left);

  426.                     }

  427.                     goto next_mb;

  428.                 }

  429.             }

  430.             block += 64;

  431.             mb++;

  432.         }

  433.         /* all blocks are finished, so the extra bytes can be used at

  434.            the video segment level */

  435.         bits_left = mb_bit_count - get_bits_count(&s->gb);

  436.         vs_bit_count += bits_left;

  437.         bit_copy(&vs_pb, &s->gb, bits_left);

  438.     next_mb:

  439.         mb1 += 6;

  440.         block1 += 6 * 64;

  441.     }

  442. 

  443.     /* we need a pass other the whole video segment */

  444.     flush_put_bits(&vs_pb);

  445.         

  446. #ifdef VLC_DEBUG

  447.     printf("***pass 3 size=%d\n", vs_bit_count);

  448. #endif

  449.     block = &s->block[0][0];

  450.     mb = mb_data;

  451.     init_get_bits(&s->gb, vs_bit_buffer, 5 * 80*8);

  452.     for(mb_index = 0; mb_index < 5; mb_index++) {

  453.         for(j = 0;j < 6; j++) {

  454.             if (!mb->eob_reached) {

  455. #ifdef VLC_DEBUG

  456.                 printf("start %d:%d\n", mb_index, j);

  457. #endif

  458.                 dv_decode_ac(s, mb, block, vs_bit_count);

  459.             }

  460.             block += 64;

  461.             mb++;

  462.         }

  463.     }

  464.     

  465.     /* compute idct and place blocks */

  466.     block = &s->block[0][0];

  467.     mb = mb_data;

  468.     for(mb_index = 0; mb_index < 5; mb_index++) {

  469.         v = *mb_pos_ptr++;

  470.         mb_x = v & 0xff;

  471.         mb_y = v >> 8;

  472.         y_ptr = s->picture.data[0] + (mb_y * s->picture.linesize[0] * 8) + (mb_x * 8);

  473.         if (s->sys->pix_fmt == PIX_FMT_YUV411P)

  474.             c_offset = (mb_y * s->picture.linesize[1] * 8) + ((mb_x >> 2) * 8);

  475.         else

  476.             c_offset = ((mb_y >> 1) * s->picture.linesize[1] * 8) + ((mb_x >> 1) * 8);

  477.         for(j = 0;j < 6; j++) {

  478.             idct_put = s->idct_put[mb->dct_mode];

  479.             if (j < 4) {

  480.                 if (s->sys->pix_fmt == PIX_FMT_YUV411P && mb_x < (704 / 8)) {

  481.                     /* NOTE: at end of line, the macroblock is handled as 420 */

  482.                     idct_put(y_ptr + (j * 8), s->picture.linesize[0], block);

  483.                 } else {

  484.                     idct_put(y_ptr + ((j & 1) * 8) + ((j >> 1) * 8 * s->picture.linesize[0]),

  485.                              s->picture.linesize[0], block);

  486.                 }

  487.             } else {

  488.                 if (s->sys->pix_fmt == PIX_FMT_YUV411P && mb_x >= (704 / 8)) {

  489.                     uint64_t aligned_pixels[64/8];

  490.                     uint8_t *pixels= (uint8_t*)aligned_pixels;

  491. 		    uint8_t *c_ptr, *c_ptr1, *ptr;

  492.                     int y, linesize;

  493.                     /* NOTE: at end of line, the macroblock is handled as 420 */

  494.                     idct_put(pixels, 8, block);

  495.                     linesize = s->picture.linesize[6 - j];

  496.                     c_ptr = s->picture.data[6 - j] + c_offset;

  497.                     ptr = pixels;

  498.                     for(y = 0;y < 8; y++) {

  499.                         /* convert to 411P */

  500.                         c_ptr1 = c_ptr + 8*linesize;

  501.                         c_ptr[0]= ptr[0]; c_ptr1[0]= ptr[4];

  502.                         c_ptr[1]= ptr[1]; c_ptr1[1]= ptr[5];

  503.                         c_ptr[2]= ptr[2]; c_ptr1[2]= ptr[6];

  504.                         c_ptr[3]= ptr[3]; c_ptr1[3]= ptr[7];

  505.                         c_ptr += linesize;

  506.                         ptr += 8;

  507.                     }

  508.                 } else {

  509.                     /* don't ask me why they inverted Cb and Cr ! */

  510.                     idct_put(s->picture.data[6 - j] + c_offset, 

  511.                              s->picture.linesize[6 - j], block);

  512.                 }

  513.             }

  514.             block += 64;

  515.             mb++;

  516.         }

  517.     }

  518. }

  519. 

  520. /* Converts run and level (where level != 0) pair into vlc, returning bit size */

  521. static inline int dv_rl2vlc(int run, int l, uint32_t* vlc)

  522. {

  523.     int sign = l >> 8;

  524.     int level = (l ^ sign) - sign;

  525.     int size;

  526.     

  527.     sign = (sign & 1);

  528. 

  529.     if (run < 15 && level < 23 && dv_vlc_codes[run][level] != -1) {

  530.         *vlc = (dv_vlc_bits[dv_vlc_codes[run][level]] << 1) | sign; 

  531. 	size = dv_vlc_len[dv_vlc_codes[run][level]] + 1;

  532.     }

  533.     else { 

  534. 	if (level < 23) {

  535. 	    *vlc = (dv_vlc_bits[dv_vlc_codes[0][level]] << 1) | sign; 

  536. 	    size = dv_vlc_len[dv_vlc_codes[0][level]] + 1;

  537. 	} else {

  538. 	    *vlc = 0xfe00 | (level << 1) | sign;

  539. 	    size = 16;

  540. 	}

  541. 

  542. 	switch(run) {

  543. 	case 0:

  544. 	    break;

  545. 	case 1:

  546. 	case 2:

  547. 	    *vlc |= ((0x7ce | (run - 1)) << size);

  548. 	    size += 11;

  549. 	    break;

  550. 	case 3:

  551. 	case 4:

  552. 	case 5:

  553. 	case 6:

  554. 	    *vlc |= ((0xfac | (run - 3)) << size);

  555. 	    size += 12;

  556. 	    break;

  557. 	default:

  558. 	    *vlc |= ((0x1f80 | (run - 1)) << size);

  559. 	    size += 13;

  560. 	    break;

  561. 	}

  562.     }

  563.     

  564.     return size;

  565. }

  566. 

  567. typedef struct EncBlockInfo {

  568.     int qno;

  569.     int cno;

  570.     int dct_mode;

  571.     int block_size;

  572.     DCTELEM *mb;

  573.     PutBitContext pb;

  574.     const uint8_t* zigzag_scan;

  575.     uint8_t *dv_shift;

  576. } EncBlockInfo;

  577. 

  578. static inline int dv_bits_left(EncBlockInfo* bi)

  579. {

  580.     return (bi->block_size - get_bit_count(&bi->pb));

  581. }

  582. 

  583. static inline void dv_encode_ac(EncBlockInfo* bi, PutBitContext* heap)

  584. {

  585.     int i, level, size, run = 0;

  586.     uint32_t vlc;

  587.     PutBitContext* cpb = &bi->pb;

  588.     int bias = (bi->cno == 3);

  589.     

  590.     for (i=1; i<64; i++) {

  591.        level = bi->mb[bi->zigzag_scan[i]] / (1<<(bi->dv_shift[i] + bias));

  592.        if (level != 0) {

  593. 	   size = dv_rl2vlc(run, level, &vlc);

  594. put_vlc:

  595. 

  596. #ifdef VLC_DEBUG

  597.            printf(" %3d:%3d", run, level);

  598. #endif

  599. 	   if (cpb == &bi->pb && size > dv_bits_left(bi)) {

  600. 	       size -= dv_bits_left(bi);

  601. 	       put_bits(cpb, dv_bits_left(bi), vlc >> size);

  602. 	       vlc = vlc & ((1<<size)-1);

  603. 	       cpb = heap;

  604. 	   }

  605. 	   put_bits(cpb, size, vlc);

  606. 	   run = 0;

  607.        } else

  608. 	   run++;

  609.     }

  610.    

  611.     if (i == 64) {

  612.         size = 4; vlc = 6; /* End Of Block stamp */

  613. 	goto put_vlc;

  614.     }

  615. }

  616. 

  617. static inline void dv_redistr_bits(EncBlockInfo* bi, int count, uint8_t* extra_data, int extra_bits, PutBitContext* heap)

  618. {

  619.     int i;

  620.     GetBitContext gb;

  621.     

  622.     init_get_bits(&gb, extra_data, extra_bits);

  623.     

  624.     for (i=0; i<count; i++) {

  625.        int bits_left = dv_bits_left(bi);

  626. #ifdef VLC_DEBUG

  627.        if (bits_left)

  628.            printf("------------> inserting %d bytes in %d:%d\n", bits_left, i/6, i%6);

  629. #endif

  630.        if (bits_left > extra_bits) {

  631.            bit_copy(&bi->pb, &gb, extra_bits); 

  632. 	   extra_bits = 0;

  633. 	   break;

  634.        } else

  635.            bit_copy(&bi->pb, &gb, bits_left);

  636. 	   

  637.        extra_bits -= bits_left;

  638.        bi++;

  639.     }

  640.     

  641.     if (extra_bits > 0 && heap)

  642. 	bit_copy(heap, &gb, extra_bits);

  643. }

  644. 

  645. static inline void dv_set_class_number(EncBlockInfo* bi, int j)

  646. {

  647.     int i, max_ac = 0;

  648. 

  649.     for (i=1; i<64; i++) {

  650.        int ac = abs(bi->mb[ff_zigzag_direct[i]]) / 4;

  651.        if (max_ac < ac)

  652.            max_ac = ac;

  653.     }

  654.     if (max_ac < 12)

  655.         bi->cno = j;

  656.     else if (max_ac < 24)

  657.         bi->cno = j + 1;

  658.     else if (max_ac < 36)

  659.         bi->cno = j + 2;

  660.     else

  661.         bi->cno = j + 3;

  662.     

  663.     if (bi->cno > 3)

  664.         bi->cno = 3;

  665. }

  666. 

  667. #define SQ(a) ((a)*(a))

  668. static int dv_score_lines(DCTELEM *s, int stride) {

  669.     int score=0;

  670.     int x, y;

  671.     

  672.     for(y=0; y<4; y++) {

  673.         for(x=0; x<8; x+=4){

  674.             score+= SQ(s[x  ] - s[x  +stride]) + SQ(s[x+1] - s[x+1+stride]) 

  675.                    +SQ(s[x+2] - s[x+2+stride]) + SQ(s[x+3] - s[x+3+stride]);

  676.         }

  677.         s+= stride;

  678.     }

  679.     

  680.     return score;

  681. }

  682. 

  683. /*

  684.  * This is a very rough initial implementaion. The performance is

  685.  * horrible and the weighting is missing. But it's missing from the 

  686.  * decoding step also -- so at least we're on the same page with decoder ;-)

  687.  */

  688. static inline void dv_encode_video_segment(DVVideoDecodeContext *s, 

  689.                                            uint8_t *dif, 

  690.                                            const uint16_t *mb_pos_ptr)

  691. {

  692.     int mb_index, i, j, v;

  693.     int mb_x, mb_y, c_offset, linesize; 

  694.     uint8_t*  y_ptr;

  695.     uint8_t*  data;

  696.     int       do_edge_wrap;

  697.     DCTELEM  *block;

  698.     EncBlockInfo  enc_blks[5*6];

  699.     EncBlockInfo* enc_blk;

  700.     int       free_vs_bits;

  701.     int extra_bits;

  702.     PutBitContext extra_vs;

  703.     uint8_t   extra_vs_data[5*6*128];

  704.     uint8_t   extra_mb_data[6*128];

  705. 

  706.     int       QNO = 15;

  707.    

  708.     /* Stage 1 -- doing DCT on 5 MBs */

  709.     block = &s->block[0][0];

  710.     enc_blk = &enc_blks[0];

  711.     for(mb_index = 0; mb_index < 5; mb_index++) {

  712.         v = *mb_pos_ptr++;

  713.         mb_x = v & 0xff;

  714.         mb_y = v >> 8;

  715.         y_ptr = s->picture.data[0] + (mb_y * s->picture.linesize[0] * 8) + (mb_x * 8);

  716. 	c_offset = (s->sys->pix_fmt == PIX_FMT_YUV411P) ?

  717. 	           ((mb_y * s->picture.linesize[1] * 8) + ((mb_x >> 2) * 8)) :

  718. 		   (((mb_y >> 1) * s->picture.linesize[1] * 8) + ((mb_x >> 1) * 8));

  719. 	do_edge_wrap = 0;

  720.         for(j = 0;j < 6; j++) {

  721.             if (j < 4) {  /* Four Y blocks */

  722. 		/* NOTE: at end of line, the macroblock is handled as 420 */

  723. 		if (s->sys->pix_fmt == PIX_FMT_YUV411P && mb_x < (704 / 8)) {

  724.                     data = y_ptr + (j * 8);

  725.                 } else {

  726.                     data = y_ptr + ((j & 1) * 8) + ((j >> 1) * 8 * s->picture.linesize[0]);

  727.                 }

  728. 		linesize = s->picture.linesize[0];

  729.             } else {      /* Cr and Cb blocks */

  730. 	        /* don't ask Fabrice why they inverted Cb and Cr ! */

  731. 	        data = s->picture.data[6 - j] + c_offset;

  732. 		linesize = s->picture.linesize[6 - j];

  733. 		if (s->sys->pix_fmt == PIX_FMT_YUV411P && mb_x >= (704 / 8))

  734. 		    do_edge_wrap = 1;

  735. 	    }	

  736.             

  737. 	    /* Everything is set up -- now just copy data -> DCT block */

  738. 	    if (do_edge_wrap) {  /* Edge wrap copy: 4x16 -> 8x8 */

  739. 		uint8_t* d;

  740. 		DCTELEM *b = block;

  741. 	        for (i=0;i<8;i++) {

  742. 		   d = data + 8 * linesize;

  743. 		   b[0] = data[0]; b[1] = data[1]; b[2] = data[2]; b[3] = data[3];

  744.                    b[4] =    d[0]; b[5] =    d[1]; b[6] =    d[2]; b[7] =    d[3];

  745. 		   data += linesize;

  746. 		   b += 8;

  747. 		}

  748. 	    } else {             /* Simple copy: 8x8 -> 8x8 */

  749. 	        s->get_pixels(block, data, linesize);

  750. 	    }

  751. 	  

  752. 	    if (dv_score_lines(block, 8) + dv_score_lines(block+8*4, 8) - 100 >

  753. 	        dv_score_lines(block, 16) + dv_score_lines(block+8, 16)) {

  754.                enc_blk->dct_mode = 1;

  755. 	       enc_blk->zigzag_scan = ff_zigzag248_direct; 

  756. 	    } else {

  757. 	       enc_blk->dct_mode = 0;

  758. 	       enc_blk->zigzag_scan = ff_zigzag_direct;

  759. 	    }

  760. 	    enc_blk->mb = block;

  761.             enc_blk->block_size = block_sizes[j];

  762. 	    

  763. 	    s->fdct[enc_blk->dct_mode](block);

  764. 	    

  765. 	    dv_set_class_number(enc_blk, j/4*(j%2));

  766. 

  767. 	    block += 64;

  768. 	    enc_blk++;

  769.         }

  770.     }

  771. 

  772.     /* Stage 2 -- encoding by trial-and-error */

  773. encode_vs:

  774.     enc_blk = &enc_blks[0];

  775.     for (i=0; i<5; i++) {

  776.        uint8_t* p = dif + i*80 + 4;

  777.        for (j=0; j<6; j++) {

  778.           enc_blk->qno = QNO;

  779. 	  enc_blk->dv_shift = &(s->dv_dct_shift[0]

  780. 	                           [QNO + dv_quant_offset[enc_blk->cno]][0]);

  781. 	  init_put_bits(&enc_blk->pb, p, block_sizes[j]/8);

  782. 	  enc_blk++;

  783. 	  p += block_sizes[j]/8;

  784.        }

  785.     }

  786. 

  787.     init_put_bits(&extra_vs, extra_vs_data, sizeof(extra_vs_data));

  788.     free_vs_bits = 0;

  789.     enc_blk = &enc_blks[0];

  790.     for (i=0; i<5; i++) {

  791.        PutBitContext extra_mb;

  792.        EncBlockInfo* enc_blk2 = enc_blk;

  793.        int free_mb_bits = 0;

  794. 

  795.        init_put_bits(&extra_mb, extra_mb_data, sizeof(extra_mb_data));

  796.        dif[i*80 + 3] = enc_blk->qno;

  797.        

  798.        for (j=0; j<6; j++) {

  799. 	  uint16_t dc = ((enc_blk->mb[0] >> 3) - 1024) >> 2;

  800. 

  801. 	  put_bits(&enc_blk->pb, 9, dc);

  802. 	  put_bits(&enc_blk->pb, 1, enc_blk->dct_mode);

  803. 	  put_bits(&enc_blk->pb, 2, enc_blk->cno);

  804. 

  805. #ifdef VLC_DEBUG

  806.           printf("[%d, %d]: ", i, j);

  807. #endif

  808. 	  dv_encode_ac(enc_blk, &extra_mb);

  809. #ifdef VLC_DEBUG

  810.           printf("\n");

  811. #endif

  812. 	  

  813. 	  free_mb_bits += dv_bits_left(enc_blk);

  814. 	  enc_blk++;

  815.        }

  816.        

  817.        /* We can't flush extra_mb just yet -- since it'll round up bit number */

  818.        extra_bits = get_bit_count(&extra_mb);

  819.        if (free_mb_bits > extra_bits)

  820.            free_vs_bits += free_mb_bits - extra_bits;

  821.     

  822.        if (extra_bits) {  /* FIXME: speed up things when free_mb_bits == 0 */

  823.            flush_put_bits(&extra_mb);

  824.            dv_redistr_bits(enc_blk2, 6, extra_mb_data, extra_bits, &extra_vs);

  825.        }

  826.     }

  827.     

  828.     /* We can't flush extra_mb just yet -- since it'll round up bit number */

  829.     extra_bits = get_bit_count(&extra_vs);

  830.     if (extra_bits > free_vs_bits && QNO) { /* FIXME: very crude trial-and-error */

  831.         QNO--;

  832. 	goto encode_vs;

  833.     }

  834.     

  835.     if (extra_bits) {

  836.         flush_put_bits(&extra_vs);

  837.         dv_redistr_bits(&enc_blks[0], 5*6, extra_vs_data, extra_bits, NULL);

  838.     }

  839. 

  840.     for (i=0; i<6*5; i++) {

  841.        flush_put_bits(&enc_blks[i].pb);

  842. #ifdef VLC_DEBUG

  843.        printf("[%d:%d] qno=%d cno=%d\n", i/6, i%6, enc_blks[i].qno, enc_blks[i].cno);

  844. #endif

  845.     }

  846. }

  847. 

  848. /* NOTE: exactly one frame must be given (120000 bytes for NTSC,

  849.    144000 bytes for PAL) */

  850. static int dvvideo_decode_frame(AVCodecContext *avctx, 

  851.                                  void *data, int *data_size,

  852.                                  uint8_t *buf, int buf_size)

  853. {

  854.     DVVideoDecodeContext *s = avctx->priv_data;

  855.     int ds, vs;

  856.     const uint16_t *mb_pos_ptr;

  857.     

  858.     s->sys = dv_frame_profile(buf);

  859.     if (!s->sys || buf_size < s->sys->frame_size)

  860.         return -1; /* NOTE: we only accept several full frames */

  861. 

  862. 	

  863.     if(s->picture.data[0])

  864.         avctx->release_buffer(avctx, &s->picture);

  865.     

  866.     s->picture.reference = 0;

  867.     avctx->pix_fmt = s->sys->pix_fmt;

  868.     avctx->width = s->sys->width;

  869.     avctx->height = s->sys->height;

  870.     if(avctx->get_buffer(avctx, &s->picture) < 0) {

  871.         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");

  872.         return -1;

  873.     }

  874.     s->picture.interlaced_frame = 1;

  875.     s->picture.top_field_first = 0;

  876. 

  877.     /* for each DIF segment */

  878.     mb_pos_ptr = s->sys->video_place;

  879.     for (ds = 0; ds < s->sys->difseg_size; ds++) {

  880.         buf += 6 * 80; /* skip DIF segment header */

  881.         

  882.         for(vs = 0; vs < 27; vs++) {

  883.             if ((vs % 3) == 0)

  884. 	        buf += 80; /* skip audio block */

  885.             

  886. #ifdef VLC_DEBUG

  887.             printf("********************* %d, %d **********************\n", ds, vs);

  888. #endif

  889. 	    dv_decode_video_segment(s, buf, mb_pos_ptr);

  890.             buf += 5 * 80;

  891.             mb_pos_ptr += 5;

  892.         }

  893.     }

  894. 

  895.     emms_c();

  896. 

  897.     /* return image */

  898.     *data_size = sizeof(AVFrame);

  899.     *(AVFrame*)data= s->picture;

  900.     

  901.     return s->sys->frame_size;

  902. }

  903. 

  904. static int dvvideo_encode_frame(AVCodecContext *c, uint8_t *buf, int buf_size, 

  905.                                 void *data)

  906. {

  907.     DVVideoDecodeContext *s = c->priv_data;

  908.     const uint16_t *mb_pos_ptr;

  909.     int ds, vs;

  910. 

  911.     s->sys = dv_codec_profile(c);

  912.     if (!s->sys)

  913. 	return -1;

  914.     

  915.     c->pix_fmt = s->sys->pix_fmt;

  916.     s->picture = *((AVFrame *)data);

  917. 

  918.     /* for each DIF segment */

  919.     mb_pos_ptr = s->sys->video_place;

  920.     for (ds = 0; ds < s->sys->difseg_size; ds++) {

  921.         buf += 6 * 80; /* skip DIF segment header */

  922.         

  923.         for(vs = 0; vs < 27; vs++) {

  924.             if ((vs % 3) == 0)

  925. 	        buf += 80; /* skip audio block */

  926. 

  927. #ifdef VLC_DEBUG

  928.             printf("********************* %d, %d **********************\n", ds, vs);

  929. #endif

  930. 	    dv_encode_video_segment(s, buf, mb_pos_ptr);

  931.             buf += 5 * 80;

  932.             mb_pos_ptr += 5;

  933.         }

  934.     }

  935. 

  936.     emms_c();

  937.     return s->sys->frame_size;

  938. }

  939. 

  940. static int dvvideo_end(AVCodecContext *avctx)

  941. {

  942.     avcodec_default_free_buffers(avctx);    

  943.     return 0;

  944. }

  945. 

  946. AVCodec dvvideo_decoder = {

  947.     "dvvideo",

  948.     CODEC_TYPE_VIDEO,

  949.     CODEC_ID_DVVIDEO,

  950.     sizeof(DVVideoDecodeContext),

  951.     dvvideo_init,

  952.     dvvideo_encode_frame,

  953.     dvvideo_end,

  954.     dvvideo_decode_frame,

  955.     CODEC_CAP_DR1,

  956.     NULL

  957. };