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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.     GetBitContext gb;

  39.     AVFrame picture;

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

  41.     

  42.     /* FIXME: the following is extracted from DSP */

  43.     uint8_t dv_zigzag[2][64];

  44.     uint8_t idct_permutation[64];

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

  46.     void (*fdct)(DCTELEM *block);

  47.     

  48.     /* XXX: move it to static storage ? */

  49.     uint8_t dv_shift[2][22][64];

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

  51. } DVVideoDecodeContext;

  52. 

  53. #define TEX_VLC_BITS 9

  54. /* XXX: also include quantization */

  55. static RL_VLC_ELEM *dv_rl_vlc[1];

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

  57. 

  58. static void dv_build_unquantize_tables(DVVideoDecodeContext *s)

  59. {

  60.     int i, q, j;

  61. 

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

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

  64.         /* 88 unquant */

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

  66.             /* 88 table */

  67.             j = s->idct_permutation[i];

  68.             s->dv_shift[0][q][j] =

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

  70.         }

  71.         

  72.         /* 248 unquant */

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

  74.             /* 248 table */

  75.             s->dv_shift[1][q][i] =  

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

  77.         }

  78.     }

  79. }

  80. 

  81. static int dvvideo_init(AVCodecContext *avctx)

  82. {

  83.     DVVideoDecodeContext *s = avctx->priv_data;

  84.     MpegEncContext s2;

  85.     static int done=0;

  86. 

  87.     if (!done) {

  88.         int i;

  89.         VLC dv_vlc;

  90. 

  91.         done = 1;

  92. 

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

  94.            to accelerate the parsing of partial codes */

  95.         init_vlc(&dv_vlc, TEX_VLC_BITS, NB_DV_VLC, 

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

  97. 

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

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

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

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

  102.             int level, run;

  103.         

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

  105.                 run= 0;

  106.                 level= code;

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

  108.                 /* EOB */

  109.                 run = 0;

  110.                 level = 256;

  111.             } else {

  112.                 run=   dv_vlc_run[code] + 1;

  113.                 level= dv_vlc_level[code];

  114.             }

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

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

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

  118.         }

  119. 

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

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

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

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

  124. 	}

  125.     }

  126. 

  127.     /* ugly way to get the idct & scantable */

  128.     /* XXX: fix it */

  129.     memset(&s2, 0, sizeof(MpegEncContext));

  130.     s2.avctx = avctx;

  131.     dsputil_init(&s2.dsp, avctx);

  132.     if (DCT_common_init(&s2) < 0)

  133.        return -1;

  134. 

  135.     s->get_pixels = s2.dsp.get_pixels;

  136.     s->fdct = s2.dsp.fdct;

  137.     

  138.     s->idct_put[0] = s2.dsp.idct_put;

  139.     memcpy(s->idct_permutation, s2.dsp.idct_permutation, 64);

  140.     memcpy(s->dv_zigzag[0], s2.intra_scantable.permutated, 64);

  141. 

  142.     /* XXX: use MMX also for idct248 */

  143.     s->idct_put[1] = simple_idct248_put;

  144.     memcpy(s->dv_zigzag[1], dv_248_zigzag, 64);

  145. 

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

  147.     dv_build_unquantize_tables(s);

  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.     

  153.     return 0;

  154. }

  155. 

  156. // #define VLC_DEBUG

  157. 

  158. typedef struct BlockInfo {

  159.     const uint8_t *shift_table;

  160.     const uint8_t *scan_table;

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

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

  163.     uint8_t dct_mode;

  164.     uint8_t partial_bit_count;

  165.     uint16_t partial_bit_buffer;

  166.     int shift_offset;

  167. } BlockInfo;

  168. 

  169. /* block size in bits */

  170. static const uint16_t block_sizes[6] = {

  171.     112, 112, 112, 112, 80, 80

  172. };

  173. 

  174. #ifndef ALT_BITSTREAM_READER

  175. #warning only works with ALT_BITSTREAM_READER

  176. #endif

  177. 

  178. /* decode ac coefs */

  179. static void dv_decode_ac(DVVideoDecodeContext *s, 

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

  181. {

  182.     int last_re_index;

  183.     int shift_offset = mb->shift_offset;

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

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

  186.     int pos = mb->pos;

  187.     int level, pos1, sign, run;

  188.     int partial_bit_count;

  189. #ifndef ALT_BITSTREAM_READER //FIXME

  190.     int re_index=0; 

  191.     int re1_index=0;

  192. #endif

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

  194.     

  195. #ifdef VLC_DEBUG

  196.     printf("start\n");

  197. #endif

  198. 

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

  200.     partial_bit_count = mb->partial_bit_count;

  201.     if (partial_bit_count > 0) {

  202.         uint8_t buf[4];

  203.         uint32_t v;

  204.         int l, l1;

  205.         GetBitContext gb1;

  206. 

  207.         /* build the dummy bit buffer */

  208.         l = 16 - partial_bit_count;

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

  210. #ifdef VLC_DEBUG

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

  212. #endif

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

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

  215.         buf[1] = v;

  216. #ifdef VLC_DEBUG

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

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

  219. #endif

  220.         /* try to read the codeword */

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

  222.         {

  223.             OPEN_READER(re1, &gb1);

  224.             UPDATE_CACHE(re1, &gb1);

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

  226.                        TEX_VLC_BITS, 2);

  227.             l = re1_index;

  228.             CLOSE_READER(re1, &gb1);

  229.         }

  230. #ifdef VLC_DEBUG

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

  232. #endif

  233.         /* compute codeword length */

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

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

  236.         l -= partial_bit_count;

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

  238.             return;

  239.         /* skip read bits */

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

  241.         re_index += l;

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

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

  244.         mb->partial_bit_count = 0;

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

  246.         goto handle_vlc;

  247.     }

  248. 

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

  250.     for(;;) {

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

  252. #ifdef VLC_DEBUG

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

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

  255. #endif

  256.         last_re_index = re_index;

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

  258.                    TEX_VLC_BITS, 2);

  259.     handle_vlc:

  260. #ifdef VLC_DEBUG

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

  262. #endif

  263.         if (level == 256) {

  264.             if (re_index > last_index) {

  265.             cannot_read:

  266.                 /* put position before read code */

  267.                 re_index = last_re_index;

  268.                 mb->eob_reached = 0;

  269.                 break;

  270.             }

  271.             /* EOB */

  272.             mb->eob_reached = 1;

  273.             break;

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

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

  276.                 goto cannot_read;

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

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

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

  280.             pos += run;

  281.             /* error */

  282.             if (pos >= 64) {

  283.                 goto read_error;

  284.             }

  285.             pos1 = scan_table[pos];

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

  287.             block[pos1] = level;

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

  289.         } else {

  290.             if (re_index > last_index)

  291.                 goto cannot_read;

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

  293.                sign is coded */

  294.             pos += run;

  295.             /* error */

  296.             if (pos >= 64) {

  297.             read_error:

  298. #if defined(VLC_DEBUG) || 1

  299.                 fprintf(stderr, "error pos=%d\n", pos);

  300. #endif

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

  302.                 mb->eob_reached = 1;

  303.                 break;

  304.             }

  305.         }

  306.     }

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

  308.     mb->pos = pos;

  309. }

  310. 

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

  312. {

  313.     while (bits_left >= 16) {

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

  315.         bits_left -= 16;

  316.     }

  317.     if (bits_left > 0) {

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

  319.     }

  320. }

  321. 

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

  323. static inline void dv_decode_video_segment(DVVideoDecodeContext *s, 

  324.                                            uint8_t *buf_ptr1, 

  325.                                            const uint16_t *mb_pos_ptr)

  326. {

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

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

  329.     DCTELEM *block, *block1;

  330.     int c_offset, bits_left;

  331.     uint8_t *y_ptr;

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

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

  334.     uint8_t *buf_ptr;

  335.     PutBitContext pb, vs_pb;

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

  337.     int mb_bit_count;

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

  339.     int vs_bit_count;

  340.     

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

  342. 

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

  344.     buf_ptr = buf_ptr1;

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

  346.     mb1 = mb_data;

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

  348.     vs_bit_count = 0;

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

  350.         /* skip header */

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

  352.         buf_ptr += 4;

  353.         init_put_bits(&pb, mb_bit_buffer, 80, NULL, NULL);

  354.         mb_bit_count = 0;

  355.         mb = mb1;

  356.         block = block1;

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

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

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

  360.             

  361.             /* get the dc */

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

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

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

  365.             mb->dct_mode = dct_mode;

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

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

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

  369.             mb->shift_table = s->dv_shift[dct_mode]

  370.                 [quant + dv_quant_offset[class1]];

  371.             dc = dc << 2;

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

  373.                standard IDCT */

  374.             dc += 1024;

  375.             block[0] = dc;

  376.             last_index = block_sizes[j];

  377.             buf_ptr += last_index >> 3;

  378.             mb->pos = 0;

  379.             mb->partial_bit_count = 0;

  380. 

  381. #ifdef VLC_DEBUG

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

  383. #endif

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

  385. 

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

  387.                block is finished */

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

  389.             if (mb->eob_reached) {

  390.                 mb->partial_bit_count = 0;

  391.                 mb_bit_count += bits_left;

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

  393.             } else {

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

  395.                    been parsed */

  396.                 mb->partial_bit_count = bits_left;

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

  398.             }

  399.             block += 64;

  400.             mb++;

  401.         }

  402.         

  403.         flush_put_bits(&pb);

  404. 

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

  406. #ifdef VLC_DEBUG

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

  408. #endif

  409.         block = block1;

  410.         mb = mb1;

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

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

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

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

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

  416.                 if (!mb->eob_reached) {

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

  418.                        so we add the remaining bytes */

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

  420.                     if (bits_left > 0) {

  421.                         mb->partial_bit_count += bits_left;

  422.                         mb->partial_bit_buffer = 

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

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

  425.                     }

  426.                     goto next_mb;

  427.                 }

  428.             }

  429.             block += 64;

  430.             mb++;

  431.         }

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

  433.            the video segment level */

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

  435.         vs_bit_count += bits_left;

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

  437.     next_mb:

  438.         mb1 += 6;

  439.         block1 += 6 * 64;

  440.     }

  441. 

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

  443.     flush_put_bits(&vs_pb);

  444.         

  445. #ifdef VLC_DEBUG

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

  447. #endif

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

  449.     mb = mb_data;

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

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

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

  453.             if (!mb->eob_reached) {

  454. #ifdef VLC_DEBUG

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

  456. #endif

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

  458.             }

  459.             block += 64;

  460.             mb++;

  461.         }

  462.     }

  463.     

  464.     /* compute idct and place blocks */

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

  466.     mb = mb_data;

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

  468.         v = *mb_pos_ptr++;

  469.         mb_x = v & 0xff;

  470.         mb_y = v >> 8;

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

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

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

  474.         else

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

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

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

  478.             if (j < 4) {

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

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

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

  482.                 } else {

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

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

  485.                 }

  486.             } else {

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

  488.                     uint8_t pixels[64], *c_ptr, *c_ptr1, *ptr;

  489.                     int y, linesize;

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

  491.                     idct_put(pixels, 8, block);

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

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

  494.                     ptr = pixels;

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

  496.                         /* convert to 411P */

  497.                         c_ptr1 = c_ptr + 8*linesize;

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

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

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

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

  502.                         c_ptr += linesize;

  503.                         ptr += 8;

  504.                     }

  505.                 } else {

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

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

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

  509.                 }

  510.             }

  511.             block += 64;

  512.             mb++;

  513.         }

  514.     }

  515. }

  516. 

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

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

  519. {

  520.     int sign = l >> 8;

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

  522.     int size;

  523.     

  524.     sign = (sign & 1);

  525. 

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

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

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

  529.     }

  530.     else { 

  531. 	if (level < 23) {

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

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

  534. 	} else {

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

  536. 	    size = 16;

  537. 	}

  538. 

  539. 	switch(run) {

  540. 	case 0:

  541. 	    break;

  542. 	case 1:

  543. 	case 2:

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

  545. 	    size += 11;

  546. 	    break;

  547. 	case 3:

  548. 	case 4:

  549. 	case 5:

  550. 	case 6:

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

  552. 	    size += 12;

  553. 	    break;

  554. 	default:

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

  556. 	    size += 13;

  557. 	    break;

  558. 	}

  559.     }

  560.     

  561.     return size;

  562. }

  563. 

  564. typedef struct EncBlockInfo {

  565.     int qno;

  566.     int cno;

  567.     int dct_mode;

  568.     int block_size;

  569.     DCTELEM *mb;

  570.     PutBitContext pb;

  571. } EncBlockInfo;

  572. 

  573. static inline int dv_bits_left(EncBlockInfo* bi)

  574. {

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

  576. }

  577. 

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

  579. {

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

  581.     uint32_t vlc;

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

  583.     

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

  585.        level = bi->mb[ff_zigzag_direct[i]] / 

  586.                (1<<(dv_quant_shifts[bi->qno + dv_quant_offset[bi->cno]]

  587. 			       [dv_88_areas[ff_zigzag_direct[i]]] + 4 + (bi->cno == 3)));

  588.        if (level != 0) {

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

  590. put_vlc:

  591. 

  592. #ifdef VLC_DEBUG

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

  594. #endif

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

  596. 	       size -= dv_bits_left(bi);

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

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

  599. 	       cpb = heap;

  600. 	   }

  601. 	   put_bits(cpb, size, vlc);

  602. 	   run = 0;

  603.        } else

  604. 	   run++;

  605.     }

  606.    

  607.     if (i == 64) {

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

  609. 	goto put_vlc;

  610.     }

  611. }

  612. 

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

  614. {

  615.     int i;

  616.     GetBitContext gb;

  617.     

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

  619.     

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

  621.        int bits_left = dv_bits_left(bi);

  622. #ifdef VLC_DEBUG

  623.        if (bits_left)

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

  625. #endif

  626.        if (bits_left > extra_bits) {

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

  628. 	   extra_bits = 0;

  629. 	   break;

  630.        } else

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

  632. 	   

  633.        extra_bits -= bits_left;

  634.        bi++;

  635.     }

  636.     

  637.     if (extra_bits > 0 && heap)

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

  639. }

  640. 

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

  642. {

  643.     int i, max_ac = 0;

  644. 

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

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

  647.        if (max_ac < ac)

  648.            max_ac = ac;

  649.     }

  650.     if (max_ac < 12)

  651.         bi->cno = j;

  652.     else if (max_ac < 24)

  653.         bi->cno = j + 1;

  654.     else if (max_ac < 36)

  655.         bi->cno = j + 2;

  656.     else

  657.         bi->cno = j + 3;

  658.     

  659.     if (bi->cno > 3)

  660.         bi->cno = 3;

  661. }

  662. 

  663. /*

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

  665.  * horrible and some features are missing, mainly 2-4-8 DCT encoding.

  666.  * The weighting is missing as well, but it's missing from the decoding

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

  668.  */

  669. static inline void dv_encode_video_segment(DVVideoDecodeContext *s, 

  670.                                            uint8_t *dif, 

  671.                                            const uint16_t *mb_pos_ptr)

  672. {

  673.     int mb_index, i, j, v;

  674.     int mb_x, mb_y, c_offset, linesize; 

  675.     uint8_t*  y_ptr;

  676.     uint8_t*  data;

  677.     int       do_edge_wrap;

  678.     DCTELEM  *block;

  679.     EncBlockInfo  enc_blks[5*6];

  680.     EncBlockInfo* enc_blk;

  681.     int       free_vs_bits;

  682.     int extra_bits;

  683.     PutBitContext extra_vs;

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

  685.     uint8_t   extra_mb_data[6*128];

  686. 

  687.     int       QNO = 15;

  688.    

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

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

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

  692.         v = *mb_pos_ptr++;

  693.         mb_x = v & 0xff;

  694.         mb_y = v >> 8;

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

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

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

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

  699. 	do_edge_wrap = 0;

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

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

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

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

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

  705.                 } else {

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

  707.                 }

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

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

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

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

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

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

  714. 		    do_edge_wrap = 1;

  715. 	    }	

  716.             

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

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

  719. 		uint8_t* d;

  720. 		DCTELEM *b = block;

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

  722. 		   d = data + 8 * linesize;

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

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

  725. 		   data += linesize;

  726. 		   b += 8;

  727. 		}

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

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

  730. 	    }

  731.             

  732. 	    s->fdct(block);

  733. 	    

  734. 	    block += 64;

  735.         }

  736.     }

  737. 

  738.     /* Stage 2 -- setup for encoding phase */

  739.     enc_blk = &enc_blks[0];

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

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

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

  743. 	  enc_blk->mb = block;

  744. 	  enc_blk->dct_mode = 0;

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

  746. 	  

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

  748. 	  

  749. 	  block += 64;

  750. 	  enc_blk++;

  751.        }

  752.     }

  753.    

  754.     /* Stage 3 -- encoding by trial-and-error */

  755. encode_vs:

  756.     enc_blk = &enc_blks[0];

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

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

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

  760.           enc_blk->qno = QNO;

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

  762. 	  enc_blk++;

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

  764.        }

  765.     }

  766. 

  767.     init_put_bits(&extra_vs, extra_vs_data, sizeof(extra_vs_data), NULL, NULL);

  768.     free_vs_bits = 0;

  769.     enc_blk = &enc_blks[0];

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

  771.        PutBitContext extra_mb;

  772.        EncBlockInfo* enc_blk2 = enc_blk;

  773.        int free_mb_bits = 0;

  774. 

  775.        init_put_bits(&extra_mb, extra_mb_data, sizeof(extra_mb_data), NULL, NULL);

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

  777.        

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

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

  780. 

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

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

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

  784. 

  785. #ifdef VLC_DEBUG

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

  787. #endif

  788. 	  dv_encode_ac(enc_blk, &extra_mb);

  789. #ifdef VLC_DEBUG

  790.           printf("\n");

  791. #endif

  792. 	  

  793. 	  free_mb_bits += dv_bits_left(enc_blk);

  794. 	  enc_blk++;

  795.        }

  796.        

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

  798.        extra_bits = get_bit_count(&extra_mb);

  799.        if (free_mb_bits > extra_bits)

  800.            free_vs_bits += free_mb_bits - extra_bits;

  801.     

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

  803.            flush_put_bits(&extra_mb);

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

  805.        }

  806.     }

  807.     

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

  809.     extra_bits = get_bit_count(&extra_vs);

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

  811.         QNO--;

  812. 	goto encode_vs;

  813.     }

  814.     

  815.     if (extra_bits) {

  816.         flush_put_bits(&extra_vs);

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

  818.     }

  819. 

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

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

  822. #ifdef VLC_DEBUG

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

  824. #endif

  825.     }

  826. }

  827. 

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

  829.    144000 bytes for PAL) */

  830. static int dvvideo_decode_frame(AVCodecContext *avctx, 

  831.                                  void *data, int *data_size,

  832.                                  uint8_t *buf, int buf_size)

  833. {

  834.     DVVideoDecodeContext *s = avctx->priv_data;

  835.     int ds, vs;

  836.     const uint16_t *mb_pos_ptr;

  837.     

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

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

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

  841. 

  842. 	

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

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

  845.     

  846.     s->picture.reference = 0;

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

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

  849.         fprintf(stderr, "get_buffer() failed\n");

  850.         return -1;

  851.     }

  852. 

  853.     /* for each DIF segment */

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

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

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

  857.         

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

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

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

  861.             

  862. #ifdef VLC_DEBUG

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

  864. #endif

  865. 	    dv_decode_video_segment(s, buf, mb_pos_ptr);

  866.             buf += 5 * 80;

  867.             mb_pos_ptr += 5;

  868.         }

  869.     }

  870. 

  871.     emms_c();

  872. 

  873.     /* return image */

  874.     *data_size = sizeof(AVFrame);

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

  876.     

  877.     return s->sys->frame_size;

  878. }

  879. 

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

  881.                                 void *data)

  882. {

  883.     DVVideoDecodeContext *s = c->priv_data;

  884.     const uint16_t *mb_pos_ptr;

  885.     int ds, vs;

  886. 

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

  888.     if (!s->sys)

  889. 	return -1;

  890.     

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

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

  893. 

  894.     /* for each DIF segment */

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

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

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

  898.         

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

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

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

  902. 

  903. #ifdef VLC_DEBUG

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

  905. #endif

  906. 	    dv_encode_video_segment(s, buf, mb_pos_ptr);

  907.             buf += 5 * 80;

  908.             mb_pos_ptr += 5;

  909.         }

  910.     }

  911. 

  912.     emms_c();

  913.     return s->sys->frame_size;

  914. }

  915. 

  916. static int dvvideo_end(AVCodecContext *avctx)

  917. {

  918.     avcodec_default_free_buffers(avctx);    

  919.     return 0;

  920. }

  921. 

  922. AVCodec dvvideo_decoder = {

  923.     "dvvideo",

  924.     CODEC_TYPE_VIDEO,

  925.     CODEC_ID_DVVIDEO,

  926.     sizeof(DVVideoDecodeContext),

  927.     dvvideo_init,

  928.     dvvideo_encode_frame,

  929.     dvvideo_end,

  930.     dvvideo_decode_frame,

  931.     CODEC_CAP_DR1,

  932.     NULL

  933. };