libavcodec/xvidff.c

   1 /*
   2  * Interface to xvidcore for mpeg4 encoding
   3  * Copyright (c) 2004 Adam Thayer <krevnik@comcast.net>
   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 /**
  23  * @file xvidmpeg4.c
  24  * Interface to xvidcore for MPEG-4 compliant encoding.
  25  * @author Adam Thayer (krevnik@comcast.net)
  26  */
  27
  28 #include <xvid.h>
  29 #include <unistd.h>
  30 #include "common.h"
  31 #include "avcodec.h"
  32 #include "xvid_internal.h"
  33
  34 /**
  35  * Buffer management macros.
  36  */
  37 #define BUFFER_SIZE                 1024
  38 #define BUFFER_REMAINING(x)         (BUFFER_SIZE - strlen(x))
  39 #define BUFFER_CAT(x)               (&((x)[strlen(x)]))
  40
  41 /* For PPC Use */
  42 #if HAVE_ALTIVEC==1
  43 extern int has_altivec(void);
  44 #endif
  45
  46 /**
  47  * Structure for the private XviD context.
  48  * This stores all the private context for the codec.
  49  */
  50 typedef struct xvid_context {
  51     void *encoder_handle;          /** Handle for XviD Encoder */
  52     int xsize, ysize;              /** Frame size */
  53     int vop_flags;                 /** VOP flags for XviD Encoder */
  54     int vol_flags;                 /** VOL flags for XviD Encoder */
  55     int me_flags;                  /** Motion Estimation flags */
  56     int qscale;                    /** Do we use constant scale? */
  57     int quicktime_format;          /** Are we in a QT-based format? */
  58     AVFrame encoded_picture;       /** Encoded frame information */
  59     char *twopassbuffer;           /** Character buffer for two-pass */
  60     char *old_twopassbuffer;       /** Old character buffer (two-pass) */
  61     char *twopassfile;             /** second pass temp file name */
  62     unsigned char *intra_matrix;   /** P-Frame Quant Matrix */
  63     unsigned char *inter_matrix;   /** I-Frame Quant Matrix */
  64 } xvid_context_t;
  65
  66 /**
  67  * Structure for the private first-pass plugin.
  68  */
  69 typedef struct xvid_ff_pass1 {
  70     int     version;                /** XviD version */
  71     xvid_context_t *context;        /** Pointer to private context */
  72 } xvid_ff_pass1_t;
  73
  74 /* Prototypes - See function implementation for details */
  75 int xvid_strip_vol_header(AVCodecContext *avctx, unsigned char *frame, unsigned int header_len, unsigned int frame_len);
  76 int xvid_ff_2pass(void *ref, int opt, void *p1, void *p2);
  77 void xvid_correct_framerate(AVCodecContext *avctx);
  78
  79 /**
  80  * Creates the private context for the encoder.
  81  * All buffers are allocated, settings are loaded from the user,
  82  * and the encoder context created.
  83  *
  84  * @param avctx AVCodecContext pointer to context
  85  * @return Returns 0 on success, -1 on failure
  86  */
  87 int ff_xvid_encode_init(AVCodecContext *avctx)  {
  88     int xerr, i;
  89     int xvid_flags = avctx->flags;
  90     xvid_context_t *x = avctx->priv_data;
  91     uint16_t *intra, *inter;
  92     int fd;
  93
  94     xvid_plugin_single_t single;
  95     xvid_ff_pass1_t rc2pass1;
  96     xvid_plugin_2pass2_t rc2pass2;
  97     xvid_gbl_init_t xvid_gbl_init;
  98     xvid_enc_create_t xvid_enc_create;
  99     xvid_enc_plugin_t plugins[7];
 100
 101     /* Bring in VOP flags from ffmpeg command-line */
 102     x->vop_flags = XVID_VOP_HALFPEL; /* Bare minimum quality */
 103     if( xvid_flags & CODEC_FLAG_4MV )
 104         x->vop_flags |= XVID_VOP_INTER4V; /* Level 3 */
 105     if( xvid_flags & CODEC_FLAG_TRELLIS_QUANT)
 106         x->vop_flags |= XVID_VOP_TRELLISQUANT; /* Level 5 */
 107     if( xvid_flags & CODEC_FLAG_AC_PRED )
 108         x->vop_flags |= XVID_VOP_HQACPRED; /* Level 6 */
 109     if( xvid_flags & CODEC_FLAG_GRAY )
 110         x->vop_flags |= XVID_VOP_GREYSCALE;
 111
 112     /* Decide which ME quality setting to use */
 113     x->me_flags = 0;
 114     switch( avctx->me_method ) {
 115        case ME_FULL:   /* Quality 6 */
 116            x->me_flags |=  XVID_ME_EXTSEARCH16
 117                        |   XVID_ME_EXTSEARCH8;
 118
 119        case ME_EPZS:   /* Quality 4 */
 120            x->me_flags |=  XVID_ME_ADVANCEDDIAMOND8
 121                        |   XVID_ME_HALFPELREFINE8
 122                        |   XVID_ME_CHROMA_PVOP
 123                        |   XVID_ME_CHROMA_BVOP;
 124
 125        case ME_LOG:    /* Quality 2 */
 126        case ME_PHODS:
 127        case ME_X1:
 128            x->me_flags |=  XVID_ME_ADVANCEDDIAMOND16
 129                        |   XVID_ME_HALFPELREFINE16;
 130
 131        case ME_ZERO:   /* Quality 0 */
 132        default:
 133            break;
 134     }
 135
 136     /* Decide how we should decide blocks */
 137     switch( avctx->mb_decision ) {
 138        case 2:
 139            x->vop_flags |= XVID_VOP_MODEDECISION_RD;
 140            x->me_flags |=  XVID_ME_HALFPELREFINE8_RD
 141                        |   XVID_ME_QUARTERPELREFINE8_RD
 142                        |   XVID_ME_EXTSEARCH_RD
 143                        |   XVID_ME_CHECKPREDICTION_RD;
 144        case 1:
 145            if( !(x->vop_flags & XVID_VOP_MODEDECISION_RD) )
 146                x->vop_flags |= XVID_VOP_FAST_MODEDECISION_RD;
 147            x->me_flags |=  XVID_ME_HALFPELREFINE16_RD
 148                        |   XVID_ME_QUARTERPELREFINE16_RD;
 149
 150        default:
 151            break;
 152     }
 153
 154     /* Bring in VOL flags from ffmpeg command-line */
 155     x->vol_flags = 0;
 156     if( xvid_flags & CODEC_FLAG_GMC ) {
 157         x->vol_flags |= XVID_VOL_GMC;
 158         x->me_flags |= XVID_ME_GME_REFINE;
 159     }
 160     if( xvid_flags & CODEC_FLAG_QPEL ) {
 161         x->vol_flags |= XVID_VOL_QUARTERPEL;
 162         x->me_flags |= XVID_ME_QUARTERPELREFINE16;
 163         if( x->vop_flags & XVID_VOP_INTER4V )
 164             x->me_flags |= XVID_ME_QUARTERPELREFINE8;
 165     }
 166
 167     memset(&xvid_gbl_init, 0, sizeof(xvid_gbl_init));
 168     xvid_gbl_init.version = XVID_VERSION;
 169     xvid_gbl_init.debug = 0;
 170
 171 #ifdef ARCH_POWERPC
 172     /* XviD's PPC support is borked, use libavcodec to detect */
 173 #if HAVE_ALTIVEC==1
 174     if( has_altivec() ) {
 175         xvid_gbl_init.cpu_flags = XVID_CPU_FORCE | XVID_CPU_ALTIVEC;
 176     } else
 177 #endif
 178         xvid_gbl_init.cpu_flags = XVID_CPU_FORCE;
 179 #else
 180     /* XviD can detect on x86 */
 181     xvid_gbl_init.cpu_flags = 0;
 182 #endif
 183
 184     /* Initialize */
 185     xvid_global(NULL, XVID_GBL_INIT, &xvid_gbl_init, NULL);
 186
 187     /* Create the encoder reference */
 188     memset(&xvid_enc_create, 0, sizeof(xvid_enc_create));
 189     xvid_enc_create.version = XVID_VERSION;
 190
 191     /* Store the desired frame size */
 192     xvid_enc_create.width = x->xsize = avctx->width;
 193     xvid_enc_create.height = x->ysize = avctx->height;
 194
 195     /* XviD can determine the proper profile to use */
 196     /* xvid_enc_create.profile = XVID_PROFILE_S_L3; */
 197
 198     /* We don't use zones or threads */
 199     xvid_enc_create.zones = NULL;
 200     xvid_enc_create.num_zones = 0;
 201     xvid_enc_create.num_threads = 0;
 202
 203     xvid_enc_create.plugins = plugins;
 204     xvid_enc_create.num_plugins = 0;
 205
 206     /* Initialize Buffers */
 207     x->twopassbuffer = NULL;
 208     x->old_twopassbuffer = NULL;
 209     x->twopassfile = NULL;
 210
 211     if( xvid_flags & CODEC_FLAG_PASS1 ) {
 212         memset(&rc2pass1, 0, sizeof(xvid_ff_pass1_t));
 213         rc2pass1.version = XVID_VERSION;
 214         rc2pass1.context = x;
 215         x->twopassbuffer = av_malloc(BUFFER_SIZE);
 216         x->old_twopassbuffer = av_malloc(BUFFER_SIZE);
 217         if( x->twopassbuffer == NULL || x->old_twopassbuffer == NULL ) {
 218             av_log(avctx, AV_LOG_ERROR,
 219                 "XviD: Cannot allocate 2-pass log buffers\n");
 220             return -1;
 221         }
 222         x->twopassbuffer[0] = x->old_twopassbuffer[0] = 0;
 223
 224         plugins[xvid_enc_create.num_plugins].func = xvid_ff_2pass;
 225         plugins[xvid_enc_create.num_plugins].param = &rc2pass1;
 226         xvid_enc_create.num_plugins++;
 227     } else if( xvid_flags & CODEC_FLAG_PASS2 ) {
 228         memset(&rc2pass2, 0, sizeof(xvid_plugin_2pass2_t));
 229         rc2pass2.version = XVID_VERSION;
 230         rc2pass2.bitrate = avctx->bit_rate;
 231
 232         fd = av_tempfile("xvidff.", &(x->twopassfile));
 233         if( fd == -1 ) {
 234             av_log(avctx, AV_LOG_ERROR,
 235                 "XviD: Cannot write 2-pass pipe\n");
 236             return -1;
 237         }
 238
 239         if( avctx->stats_in == NULL ) {
 240             av_log(avctx, AV_LOG_ERROR,
 241                 "XviD: No 2-pass information loaded for second pass\n");
 242             return -1;
 243         }
 244
 245         if( strlen(avctx->stats_in) >
 246               write(fd, avctx->stats_in, strlen(avctx->stats_in)) ) {
 247             close(fd);
 248             av_log(avctx, AV_LOG_ERROR,
 249                 "XviD: Cannot write to 2-pass pipe\n");
 250             return -1;
 251         }
 252
 253         close(fd);
 254         rc2pass2.filename = x->twopassfile;
 255         plugins[xvid_enc_create.num_plugins].func = xvid_plugin_2pass2;
 256         plugins[xvid_enc_create.num_plugins].param = &rc2pass2;
 257         xvid_enc_create.num_plugins++;
 258     } else if( !(xvid_flags & CODEC_FLAG_QSCALE) ) {
 259         /* Single Pass Bitrate Control! */
 260         memset(&single, 0, sizeof(xvid_plugin_single_t));
 261         single.version = XVID_VERSION;
 262         single.bitrate = avctx->bit_rate;
 263
 264         plugins[xvid_enc_create.num_plugins].func = xvid_plugin_single;
 265         plugins[xvid_enc_create.num_plugins].param = &single;
 266         xvid_enc_create.num_plugins++;
 267     }
 268
 269     /* Luminance Masking */
 270     if( 0.0 != avctx->lumi_masking ) {
 271         plugins[xvid_enc_create.num_plugins].func = xvid_plugin_lumimasking;
 272         plugins[xvid_enc_create.num_plugins].param = NULL;
 273         xvid_enc_create.num_plugins++;
 274     }
 275
 276     /* Frame Rate and Key Frames */
 277     xvid_correct_framerate(avctx);
 278     xvid_enc_create.fincr = avctx->time_base.num;
 279     xvid_enc_create.fbase = avctx->time_base.den;
 280     if( avctx->gop_size > 0 )
 281         xvid_enc_create.max_key_interval = avctx->gop_size;
 282     else
 283         xvid_enc_create.max_key_interval = 240; /* XviD's best default */
 284
 285     /* Quants */
 286     if( xvid_flags & CODEC_FLAG_QSCALE ) x->qscale = 1;
 287     else x->qscale = 0;
 288
 289     xvid_enc_create.min_quant[0] = avctx->qmin;
 290     xvid_enc_create.min_quant[1] = avctx->qmin;
 291     xvid_enc_create.min_quant[2] = avctx->qmin;
 292     xvid_enc_create.max_quant[0] = avctx->qmax;
 293     xvid_enc_create.max_quant[1] = avctx->qmax;
 294     xvid_enc_create.max_quant[2] = avctx->qmax;
 295
 296     /* Quant Matrices */
 297     x->intra_matrix = x->inter_matrix = NULL;
 298     if( avctx->mpeg_quant )
 299        x->vol_flags |= XVID_VOL_MPEGQUANT;
 300     if( (avctx->intra_matrix || avctx->inter_matrix) ) {
 301        x->vol_flags |= XVID_VOL_MPEGQUANT;
 302
 303        if( avctx->intra_matrix ) {
 304            intra = avctx->intra_matrix;
 305            x->intra_matrix = av_malloc(sizeof(unsigned char) * 64);
 306        } else
 307            intra = NULL;
 308        if( avctx->inter_matrix ) {
 309            inter = avctx->inter_matrix;
 310            x->inter_matrix = av_malloc(sizeof(unsigned char) * 64);
 311        } else
 312            inter = NULL;
 313
 314        for( i = 0; i < 64; i++ ) {
 315            if( intra )
 316                x->intra_matrix[i] = (unsigned char)intra[i];
 317            if( inter )
 318                x->inter_matrix[i] = (unsigned char)inter[i];
 319        }
 320     }
 321
 322     /* Misc Settings */
 323     xvid_enc_create.frame_drop_ratio = 0;
 324     xvid_enc_create.global = 0;
 325     if( xvid_flags & CODEC_FLAG_CLOSED_GOP )
 326         xvid_enc_create.global |= XVID_GLOBAL_CLOSED_GOP;
 327
 328     /* Determines which codec mode we are operating in */
 329     avctx->extradata = NULL;
 330     avctx->extradata_size = 0;
 331     if( xvid_flags & CODEC_FLAG_GLOBAL_HEADER ) {
 332         /* In this case, we are claiming to be MPEG4 */
 333         x->quicktime_format = 1;
 334         avctx->codec_id = CODEC_ID_MPEG4;
 335     } else {
 336         /* We are claiming to be XviD */
 337         x->quicktime_format = 0;
 338         if(!avctx->codec_tag)
 339             avctx->codec_tag = ff_get_fourcc("xvid");
 340     }
 341
 342     /* Bframes */
 343     xvid_enc_create.max_bframes = avctx->max_b_frames;
 344     xvid_enc_create.bquant_offset = 100 * avctx->b_quant_offset;
 345     xvid_enc_create.bquant_ratio = 100 * avctx->b_quant_factor;
 346     if( avctx->max_b_frames > 0  && !x->quicktime_format ) xvid_enc_create.global |= XVID_GLOBAL_PACKED;
 347
 348     /* Create encoder context */
 349     xerr = xvid_encore(NULL, XVID_ENC_CREATE, &xvid_enc_create, NULL);
 350     if( xerr ) {
 351         av_log(avctx, AV_LOG_ERROR, "XviD: Could not create encoder reference\n");
 352         return -1;
 353     }
 354
 355     x->encoder_handle = xvid_enc_create.handle;
 356     avctx->coded_frame = &x->encoded_picture;
 357
 358     return 0;
 359 }
 360
 361 /**
 362  * Encodes a single frame.
 363  *
 364  * @param avctx AVCodecContext pointer to context
 365  * @param frame Pointer to encoded frame buffer
 366  * @param buf_size Size of encoded frame buffer
 367  * @param data Pointer to AVFrame of unencoded frame
 368  * @return Returns 0 on success, -1 on failure
 369  */
 370 int ff_xvid_encode_frame(AVCodecContext *avctx,
 371                          unsigned char *frame, int buf_size, void *data) {
 372     int xerr, i;
 373     char *tmp;
 374     xvid_context_t *x = avctx->priv_data;
 375     AVFrame *picture = data;
 376     AVFrame *p = &(x->encoded_picture);
 377
 378     xvid_enc_frame_t xvid_enc_frame;
 379     xvid_enc_stats_t xvid_enc_stats;
 380
 381     /* Start setting up the frame */
 382     memset(&xvid_enc_frame, 0, sizeof(xvid_enc_frame));
 383     xvid_enc_frame.version = XVID_VERSION;
 384     memset(&xvid_enc_stats, 0, sizeof(xvid_enc_stats));
 385     xvid_enc_stats.version = XVID_VERSION;
 386     *p = *picture;
 387
 388     /* Let XviD know where to put the frame. */
 389     xvid_enc_frame.bitstream = frame;
 390     xvid_enc_frame.length = buf_size;
 391
 392     /* Initialize input image fields */
 393     if( avctx->pix_fmt != PIX_FMT_YUV420P ) {
 394         av_log(avctx, AV_LOG_ERROR, "XviD: Color spaces other than 420p not supported\n");
 395         return -1;
 396     }
 397
 398     xvid_enc_frame.input.csp = XVID_CSP_PLANAR; /* YUV420P */
 399
 400     for( i = 0; i < 4; i++ ) {
 401         xvid_enc_frame.input.plane[i] = picture->data[i];
 402         xvid_enc_frame.input.stride[i] = picture->linesize[i];
 403     }
 404
 405     /* Encoder Flags */
 406     xvid_enc_frame.vop_flags = x->vop_flags;
 407     xvid_enc_frame.vol_flags = x->vol_flags;
 408     xvid_enc_frame.motion = x->me_flags;
 409     xvid_enc_frame.type = XVID_TYPE_AUTO;
 410
 411     /* Quant Setting */
 412     if( x->qscale ) xvid_enc_frame.quant = picture->quality / FF_QP2LAMBDA;
 413     else xvid_enc_frame.quant = 0;
 414
 415     /* Matrices */
 416     xvid_enc_frame.quant_intra_matrix = x->intra_matrix;
 417     xvid_enc_frame.quant_inter_matrix = x->inter_matrix;
 418
 419     /* Encode */
 420     xerr = xvid_encore(x->encoder_handle, XVID_ENC_ENCODE,
 421         &xvid_enc_frame, &xvid_enc_stats);
 422
 423     /* Two-pass log buffer swapping */
 424     avctx->stats_out = NULL;
 425     if( x->twopassbuffer ) {
 426         tmp = x->old_twopassbuffer;
 427         x->old_twopassbuffer = x->twopassbuffer;
 428         x->twopassbuffer = tmp;
 429         x->twopassbuffer[0] = 0;
 430         if( x->old_twopassbuffer[0] != 0 ) {
 431             avctx->stats_out = x->old_twopassbuffer;
 432         }
 433     }
 434
 435     if( 0 <= xerr ) {
 436         p->quality = xvid_enc_stats.quant * FF_QP2LAMBDA;
 437         if( xvid_enc_stats.type == XVID_TYPE_PVOP )
 438             p->pict_type = FF_P_TYPE;
 439         else if( xvid_enc_stats.type == XVID_TYPE_BVOP )
 440             p->pict_type = FF_B_TYPE;
 441         else if( xvid_enc_stats.type == XVID_TYPE_SVOP )
 442             p->pict_type = FF_S_TYPE;
 443         else
 444             p->pict_type = FF_I_TYPE;
 445         if( xvid_enc_frame.out_flags & XVID_KEYFRAME ) {
 446             p->key_frame = 1;
 447             if( x->quicktime_format )
 448                 return xvid_strip_vol_header(avctx, frame,
 449                     xvid_enc_stats.hlength, xerr);
 450          } else
 451             p->key_frame = 0;
 452
 453         return xerr;
 454     } else {
 455         av_log(avctx, AV_LOG_ERROR, "XviD: Encoding Error Occurred: %i\n", xerr);
 456         return -1;
 457     }
 458 }
 459
 460 /**
 461  * Destroys the private context for the encoder.
 462  * All buffers are freed, and the XviD encoder context is destroyed.
 463  *
 464  * @param avctx AVCodecContext pointer to context
 465  * @return Returns 0, success guaranteed
 466  */
 467 int ff_xvid_encode_close(AVCodecContext *avctx) {
 468     xvid_context_t *x = avctx->priv_data;
 469
 470     xvid_encore(x->encoder_handle, XVID_ENC_DESTROY, NULL, NULL);
 471
 472     if( avctx->extradata != NULL )
 473         av_free(avctx->extradata);
 474     if( x->twopassbuffer != NULL ) {
 475         av_free(x->twopassbuffer);
 476         av_free(x->old_twopassbuffer);
 477     }
 478     if( x->twopassfile != NULL )
 479         av_free(x->twopassfile);
 480     if( x->intra_matrix != NULL )
 481         av_free(x->intra_matrix);
 482     if( x->inter_matrix != NULL )
 483         av_free(x->inter_matrix);
 484
 485     return 0;
 486 }
 487
 488 /**
 489  * Routine to create a global VO/VOL header for MP4 container.
 490  * What we do here is extract the header from the XviD bitstream
 491  * as it is encoded. We also strip the repeated headers from the
 492  * bitstream when a global header is requested for MPEG-4 ISO
 493  * compliance.
 494  *
 495  * @param avctx AVCodecContext pointer to context
 496  * @param frame Pointer to encoded frame data
 497  * @param header_len Length of header to search
 498  * @param frame_len Length of encoded frame data
 499  * @return Returns new length of frame data
 500  */
 501 int xvid_strip_vol_header(AVCodecContext *avctx,
 502                   unsigned char *frame,
 503                   unsigned int header_len,
 504                   unsigned int frame_len) {
 505     int vo_len = 0, i;
 506
 507     for( i = 0; i < header_len - 3; i++ ) {
 508         if( frame[i] == 0x00 &&
 509             frame[i+1] == 0x00 &&
 510             frame[i+2] == 0x01 &&
 511             frame[i+3] == 0xB6 ) {
 512             vo_len = i;
 513             break;
 514         }
 515     }
 516
 517     if( vo_len > 0 ) {
 518         /* We need to store the header, so extract it */
 519         if( avctx->extradata == NULL ) {
 520             avctx->extradata = av_malloc(vo_len);
 521             memcpy(avctx->extradata, frame, vo_len);
 522             avctx->extradata_size = vo_len;
 523         }
 524         /* Less dangerous now, memmove properly copies the two
 525            chunks of overlapping data */
 526         memmove(frame, &(frame[vo_len]), frame_len - vo_len);
 527         return frame_len - vo_len;
 528     } else
 529         return frame_len;
 530 }
 531
 532 /**
 533  * Routine to correct a possibly erroneous framerate being fed to us.
 534  * XviD currently chokes on framerates where the ticks per frame is
 535  * extremely large. This function works to correct problems in this area
 536  * by estimating a new framerate and taking the simpler fraction of
 537  * the two presented.
 538  *
 539  * @param avctx Context that contains the framerate to correct.
 540  */
 541 void xvid_correct_framerate(AVCodecContext *avctx) {
 542     int frate, fbase;
 543     int est_frate, est_fbase;
 544     int gcd;
 545     float est_fps, fps;
 546
 547     frate = avctx->time_base.den;
 548     fbase = avctx->time_base.num;
 549
 550     gcd = ff_gcd(frate, fbase);
 551     if( gcd > 1 ) {
 552         frate /= gcd;
 553         fbase /= gcd;
 554     }
 555
 556     if( frate <= 65000 && fbase <= 65000 ) {
 557         avctx->time_base.den = frate;
 558         avctx->time_base.num = fbase;
 559         return;
 560     }
 561
 562     fps = (float)frate / (float)fbase;
 563     est_fps = roundf(fps * 1000.0) / 1000.0;
 564
 565     est_frate = (int)est_fps;
 566     if( est_fps > (int)est_fps ) {
 567         est_frate = (est_frate + 1) * 1000;
 568         est_fbase = (int)roundf((float)est_frate / est_fps);
 569     } else
 570         est_fbase = 1;
 571
 572     gcd = ff_gcd(est_frate, est_fbase);
 573     if( gcd > 1 ) {
 574         est_frate /= gcd;
 575         est_fbase /= gcd;
 576     }
 577
 578     if( fbase > est_fbase ) {
 579         avctx->time_base.den = est_frate;
 580         avctx->time_base.num = est_fbase;
 581         av_log(avctx, AV_LOG_DEBUG,
 582             "XviD: framerate re-estimated: %.2f, %.3f%% correction\n",
 583             est_fps, (((est_fps - fps)/fps) * 100.0));
 584     } else {
 585         avctx->time_base.den = frate;
 586         avctx->time_base.num = fbase;
 587     }
 588 }
 589
 590 /*
 591  * XviD 2-Pass Kludge Section
 592  *
 593  * XviD's default 2-pass doesn't allow us to create data as we need to, so
 594  * this section spends time replacing the first pass plugin so we can write
 595  * statistic information as libavcodec requests in. We have another kludge
 596  * that allows us to pass data to the second pass in XviD without a custom
 597  * rate-control plugin.
 598  */
 599
 600 /**
 601  * Initializes the two-pass plugin and context.
 602  *
 603  * @param param Input construction parameter structure
 604  * @param handle Private context handle
 605  * @return Returns XVID_ERR_xxxx on failure, or 0 on success.
 606  */
 607 static int xvid_ff_2pass_create(xvid_plg_create_t * param,
 608                                 void ** handle) {
 609     xvid_ff_pass1_t *x = (xvid_ff_pass1_t *)param->param;
 610     char *log = x->context->twopassbuffer;
 611
 612     /* Do a quick bounds check */
 613     if( log == NULL )
 614         return XVID_ERR_FAIL;
 615
 616     /* We use snprintf() */
 617     /* This is because we can safely prevent a buffer overflow */
 618     log[0] = 0;
 619     snprintf(log, BUFFER_REMAINING(log),
 620         "# ffmpeg 2-pass log file, using xvid codec\n");
 621     snprintf(BUFFER_CAT(log), BUFFER_REMAINING(log),
 622         "# Do not modify. libxvidcore version: %d.%d.%d\n\n",
 623         XVID_VERSION_MAJOR(XVID_VERSION),
 624         XVID_VERSION_MINOR(XVID_VERSION),
 625         XVID_VERSION_PATCH(XVID_VERSION));
 626
 627     *handle = x->context;
 628     return 0;
 629 }
 630
 631 /**
 632  * Destroys the two-pass plugin context.
 633  *
 634  * @param ref Context pointer for the plugin
 635  * @param param Destrooy context
 636  * @return Returns 0, success guaranteed
 637  */
 638 static int xvid_ff_2pass_destroy(xvid_context_t *ref,
 639                                 xvid_plg_destroy_t *param) {
 640     /* Currently cannot think of anything to do on destruction */
 641     /* Still, the framework should be here for reference/use */
 642     if( ref->twopassbuffer != NULL )
 643         ref->twopassbuffer[0] = 0;
 644     return 0;
 645 }
 646
 647 /**
 648  * Enables fast encode mode during the first pass.
 649  *
 650  * @param ref Context pointer for the plugin
 651  * @param param Frame data
 652  * @return Returns 0, success guaranteed
 653  */
 654 static int xvid_ff_2pass_before(xvid_context_t *ref,
 655                                 xvid_plg_data_t *param) {
 656     int motion_remove;
 657     int motion_replacements;
 658     int vop_remove;
 659
 660     /* Nothing to do here, result is changed too much */
 661     if( param->zone && param->zone->mode == XVID_ZONE_QUANT )
 662         return 0;
 663
 664     /* We can implement a 'turbo' first pass mode here */
 665     param->quant = 2;
 666
 667     /* Init values */
 668     motion_remove = ~XVID_ME_CHROMA_PVOP &
 669                     ~XVID_ME_CHROMA_BVOP &
 670                     ~XVID_ME_EXTSEARCH16 &
 671                     ~XVID_ME_ADVANCEDDIAMOND16;
 672     motion_replacements = XVID_ME_FAST_MODEINTERPOLATE |
 673                           XVID_ME_SKIP_DELTASEARCH |
 674                           XVID_ME_FASTREFINE16 |
 675                           XVID_ME_BFRAME_EARLYSTOP;
 676     vop_remove = ~XVID_VOP_MODEDECISION_RD &
 677                  ~XVID_VOP_FAST_MODEDECISION_RD &
 678                  ~XVID_VOP_TRELLISQUANT &
 679                  ~XVID_VOP_INTER4V &
 680                  ~XVID_VOP_HQACPRED;
 681
 682     param->vol_flags &= ~XVID_VOL_GMC;
 683     param->vop_flags &= vop_remove;
 684     param->motion_flags &= motion_remove;
 685     param->motion_flags |= motion_replacements;
 686
 687     return 0;
 688 }
 689
 690 /**
 691  * Captures statistic data and writes it during first pass.
 692  *
 693  * @param ref Context pointer for the plugin
 694  * @param param Statistic data
 695  * @return Returns XVID_ERR_xxxx on failure, or 0 on success
 696  */
 697 static int xvid_ff_2pass_after(xvid_context_t *ref,
 698                                 xvid_plg_data_t *param) {
 699     char *log = ref->twopassbuffer;
 700     char *frame_types = " ipbs";
 701     char frame_type;
 702
 703     /* Quick bounds check */
 704     if( log == NULL )
 705         return XVID_ERR_FAIL;
 706
 707     /* Convert the type given to us into a character */
 708     if( param->type < 5 && param->type > 0 ) {
 709         frame_type = frame_types[param->type];
 710     } else {
 711         return XVID_ERR_FAIL;
 712     }
 713
 714     snprintf(BUFFER_CAT(log), BUFFER_REMAINING(log),
 715         "%c %d %d %d %d %d %d\n",
 716         frame_type, param->stats.quant, param->stats.kblks, param->stats.mblks,
 717         param->stats.ublks, param->stats.length, param->stats.hlength);
 718
 719     return 0;
 720 }
 721
 722 /**
 723  * Dispatch function for our custom plugin.
 724  * This handles the dispatch for the XviD plugin. It passes data
 725  * on to other functions for actual processing.
 726  *
 727  * @param ref Context pointer for the plugin
 728  * @param cmd The task given for us to complete
 729  * @param p1 First parameter (varies)
 730  * @param p2 Second parameter (varies)
 731  * @return Returns XVID_ERR_xxxx on failure, or 0 on success
 732  */
 733 int xvid_ff_2pass(void *ref, int cmd, void *p1, void *p2) {
 734     switch( cmd ) {
 735         case XVID_PLG_INFO:
 736         case XVID_PLG_FRAME:
 737             return 0;
 738
 739         case XVID_PLG_BEFORE:
 740             return xvid_ff_2pass_before(ref, p1);
 741
 742         case XVID_PLG_CREATE:
 743             return xvid_ff_2pass_create(p1, p2);
 744
 745         case XVID_PLG_AFTER:
 746             return xvid_ff_2pass_after(ref, p1);
 747
 748         case XVID_PLG_DESTROY:
 749             return xvid_ff_2pass_destroy(ref, p1);
 750
 751         default:
 752             return XVID_ERR_FAIL;
 753     }
 754 }
 755
 756 /**
 757  * XviD codec definition for libavcodec.
 758  */
 759 AVCodec xvid_encoder = {
 760     "xvid",
 761     CODEC_TYPE_VIDEO,
 762     CODEC_ID_XVID,
 763     sizeof(xvid_context_t),
 764     ff_xvid_encode_init,
 765     ff_xvid_encode_frame,
 766     ff_xvid_encode_close,
 767     .pix_fmts= (enum PixelFormat[]){PIX_FMT_YUV420P, -1},
 768 };