1/*
2 * Interface to xvidcore for mpeg4 encoding
3 * Copyright (c) 2004 Adam Thayer <krevnik@comcast.net>
4 *
5 * This file is part of Libav.
6 *
7 * Libav 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 * Libav 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 Libav; 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
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 "avcodec.h"
31#include "libavutil/cpu.h"
32#include "libavutil/intreadwrite.h"
33#include "libavutil/mathematics.h"
34#include "libxvid_internal.h"
35#if !HAVE_MKSTEMP
36#include <fcntl.h>
37#endif
38
39/**
40 * Buffer management macros.
41 */
42#define BUFFER_SIZE                 1024
43#define BUFFER_REMAINING(x)         (BUFFER_SIZE - strlen(x))
44#define BUFFER_CAT(x)               (&((x)[strlen(x)]))
45
46/**
47 * Structure for the private Xvid context.
48 * This stores all the private context for the codec.
49 */
50struct xvid_context {
51    void *encoder_handle;          /**< Handle for Xvid encoder */
52    int xsize;                     /**< Frame x size */
53    int ysize;                     /**< Frame y size */
54    int vop_flags;                 /**< VOP flags for Xvid encoder */
55    int vol_flags;                 /**< VOL flags for Xvid encoder */
56    int me_flags;                  /**< Motion Estimation flags */
57    int qscale;                    /**< Do we use constant scale? */
58    int quicktime_format;          /**< Are we in a QT-based format? */
59    AVFrame encoded_picture;       /**< Encoded frame information */
60    char *twopassbuffer;           /**< Character buffer for two-pass */
61    char *old_twopassbuffer;       /**< Old character buffer (two-pass) */
62    char *twopassfile;             /**< second pass temp file name */
63    unsigned char *intra_matrix;   /**< P-Frame Quant Matrix */
64    unsigned char *inter_matrix;   /**< I-Frame Quant Matrix */
65};
66
67/**
68 * Structure for the private first-pass plugin.
69 */
70struct xvid_ff_pass1 {
71    int     version;                /**< Xvid version */
72    struct xvid_context *context;   /**< Pointer to private context */
73};
74
75/* Prototypes - See function implementation for details */
76int xvid_strip_vol_header(AVCodecContext *avctx, unsigned char *frame, unsigned int header_len, unsigned int frame_len);
77int xvid_ff_2pass(void *ref, int opt, void *p1, void *p2);
78void xvid_correct_framerate(AVCodecContext *avctx);
79
80/* Wrapper to work around the lack of mkstemp() on mingw.
81 * Also, tries to create file in /tmp first, if possible.
82 * *prefix can be a character constant; *filename will be allocated internally.
83 * @return file descriptor of opened file (or -1 on error)
84 * and opened file name in **filename. */
85int ff_tempfile(const char *prefix, char **filename) {
86    int fd=-1;
87#if !HAVE_MKSTEMP
88    *filename = tempnam(".", prefix);
89#else
90    size_t len = strlen(prefix) + 12; /* room for "/tmp/" and "XXXXXX\0" */
91    *filename = av_malloc(len);
92#endif
93    /* -----common section-----*/
94    if (*filename == NULL) {
95        av_log(NULL, AV_LOG_ERROR, "ff_tempfile: Cannot allocate file name\n");
96        return -1;
97    }
98#if !HAVE_MKSTEMP
99    fd = open(*filename, O_RDWR | O_BINARY | O_CREAT, 0444);
100#else
101    snprintf(*filename, len, "/tmp/%sXXXXXX", prefix);
102    fd = mkstemp(*filename);
103    if (fd < 0) {
104        snprintf(*filename, len, "./%sXXXXXX", prefix);
105        fd = mkstemp(*filename);
106    }
107#endif
108    /* -----common section-----*/
109    if (fd < 0) {
110        av_log(NULL, AV_LOG_ERROR, "ff_tempfile: Cannot open temporary file %s\n", *filename);
111        return -1;
112    }
113    return fd; /* success */
114}
115
116#if CONFIG_LIBXVID_ENCODER
117
118/**
119 * Create the private context for the encoder.
120 * All buffers are allocated, settings are loaded from the user,
121 * and the encoder context created.
122 *
123 * @param avctx AVCodecContext pointer to context
124 * @return Returns 0 on success, -1 on failure
125 */
126static av_cold int xvid_encode_init(AVCodecContext *avctx)  {
127    int xerr, i;
128    int xvid_flags = avctx->flags;
129    struct xvid_context *x = avctx->priv_data;
130    uint16_t *intra, *inter;
131    int fd;
132
133    xvid_plugin_single_t single;
134    struct xvid_ff_pass1 rc2pass1;
135    xvid_plugin_2pass2_t rc2pass2;
136    xvid_gbl_init_t xvid_gbl_init;
137    xvid_enc_create_t xvid_enc_create;
138    xvid_enc_plugin_t plugins[7];
139
140    /* Bring in VOP flags from avconv command-line */
141    x->vop_flags = XVID_VOP_HALFPEL; /* Bare minimum quality */
142    if( xvid_flags & CODEC_FLAG_4MV )
143        x->vop_flags |= XVID_VOP_INTER4V; /* Level 3 */
144    if( avctx->trellis
145        )
146        x->vop_flags |= XVID_VOP_TRELLISQUANT; /* Level 5 */
147    if( xvid_flags & CODEC_FLAG_AC_PRED )
148        x->vop_flags |= XVID_VOP_HQACPRED; /* Level 6 */
149    if( xvid_flags & CODEC_FLAG_GRAY )
150        x->vop_flags |= XVID_VOP_GREYSCALE;
151
152    /* Decide which ME quality setting to use */
153    x->me_flags = 0;
154    switch( avctx->me_method ) {
155       case ME_FULL:   /* Quality 6 */
156           x->me_flags |=  XVID_ME_EXTSEARCH16
157                       |   XVID_ME_EXTSEARCH8;
158
159       case ME_EPZS:   /* Quality 4 */
160           x->me_flags |=  XVID_ME_ADVANCEDDIAMOND8
161                       |   XVID_ME_HALFPELREFINE8
162                       |   XVID_ME_CHROMA_PVOP
163                       |   XVID_ME_CHROMA_BVOP;
164
165       case ME_LOG:    /* Quality 2 */
166       case ME_PHODS:
167       case ME_X1:
168           x->me_flags |=  XVID_ME_ADVANCEDDIAMOND16
169                       |   XVID_ME_HALFPELREFINE16;
170
171       case ME_ZERO:   /* Quality 0 */
172       default:
173           break;
174    }
175
176    /* Decide how we should decide blocks */
177    switch( avctx->mb_decision ) {
178       case 2:
179           x->vop_flags |= XVID_VOP_MODEDECISION_RD;
180           x->me_flags |=  XVID_ME_HALFPELREFINE8_RD
181                       |   XVID_ME_QUARTERPELREFINE8_RD
182                       |   XVID_ME_EXTSEARCH_RD
183                       |   XVID_ME_CHECKPREDICTION_RD;
184       case 1:
185           if( !(x->vop_flags & XVID_VOP_MODEDECISION_RD) )
186               x->vop_flags |= XVID_VOP_FAST_MODEDECISION_RD;
187           x->me_flags |=  XVID_ME_HALFPELREFINE16_RD
188                       |   XVID_ME_QUARTERPELREFINE16_RD;
189
190       default:
191           break;
192    }
193
194    /* Bring in VOL flags from avconv command-line */
195    x->vol_flags = 0;
196    if( xvid_flags & CODEC_FLAG_GMC ) {
197        x->vol_flags |= XVID_VOL_GMC;
198        x->me_flags |= XVID_ME_GME_REFINE;
199    }
200    if( xvid_flags & CODEC_FLAG_QPEL ) {
201        x->vol_flags |= XVID_VOL_QUARTERPEL;
202        x->me_flags |= XVID_ME_QUARTERPELREFINE16;
203        if( x->vop_flags & XVID_VOP_INTER4V )
204            x->me_flags |= XVID_ME_QUARTERPELREFINE8;
205    }
206
207    memset(&xvid_gbl_init, 0, sizeof(xvid_gbl_init));
208    xvid_gbl_init.version = XVID_VERSION;
209    xvid_gbl_init.debug = 0;
210
211#if ARCH_PPC
212    /* Xvid's PPC support is borked, use libavcodec to detect */
213#if HAVE_ALTIVEC
214    if (av_get_cpu_flags() & AV_CPU_FLAG_ALTIVEC) {
215        xvid_gbl_init.cpu_flags = XVID_CPU_FORCE | XVID_CPU_ALTIVEC;
216    } else
217#endif
218        xvid_gbl_init.cpu_flags = XVID_CPU_FORCE;
219#else
220    /* Xvid can detect on x86 */
221    xvid_gbl_init.cpu_flags = 0;
222#endif
223
224    /* Initialize */
225    xvid_global(NULL, XVID_GBL_INIT, &xvid_gbl_init, NULL);
226
227    /* Create the encoder reference */
228    memset(&xvid_enc_create, 0, sizeof(xvid_enc_create));
229    xvid_enc_create.version = XVID_VERSION;
230
231    /* Store the desired frame size */
232    xvid_enc_create.width = x->xsize = avctx->width;
233    xvid_enc_create.height = x->ysize = avctx->height;
234
235    /* Xvid can determine the proper profile to use */
236    /* xvid_enc_create.profile = XVID_PROFILE_S_L3; */
237
238    /* We don't use zones */
239    xvid_enc_create.zones = NULL;
240    xvid_enc_create.num_zones = 0;
241
242    xvid_enc_create.num_threads = avctx->thread_count;
243
244    xvid_enc_create.plugins = plugins;
245    xvid_enc_create.num_plugins = 0;
246
247    /* Initialize Buffers */
248    x->twopassbuffer = NULL;
249    x->old_twopassbuffer = NULL;
250    x->twopassfile = NULL;
251
252    if( xvid_flags & CODEC_FLAG_PASS1 ) {
253        memset(&rc2pass1, 0, sizeof(struct xvid_ff_pass1));
254        rc2pass1.version = XVID_VERSION;
255        rc2pass1.context = x;
256        x->twopassbuffer = av_malloc(BUFFER_SIZE);
257        x->old_twopassbuffer = av_malloc(BUFFER_SIZE);
258        if( x->twopassbuffer == NULL || x->old_twopassbuffer == NULL ) {
259            av_log(avctx, AV_LOG_ERROR,
260                "Xvid: Cannot allocate 2-pass log buffers\n");
261            return -1;
262        }
263        x->twopassbuffer[0] = x->old_twopassbuffer[0] = 0;
264
265        plugins[xvid_enc_create.num_plugins].func = xvid_ff_2pass;
266        plugins[xvid_enc_create.num_plugins].param = &rc2pass1;
267        xvid_enc_create.num_plugins++;
268    } else if( xvid_flags & CODEC_FLAG_PASS2 ) {
269        memset(&rc2pass2, 0, sizeof(xvid_plugin_2pass2_t));
270        rc2pass2.version = XVID_VERSION;
271        rc2pass2.bitrate = avctx->bit_rate;
272
273        fd = ff_tempfile("xvidff.", &x->twopassfile);
274        if( fd == -1 ) {
275            av_log(avctx, AV_LOG_ERROR,
276                "Xvid: Cannot write 2-pass pipe\n");
277            return -1;
278        }
279
280        if( avctx->stats_in == NULL ) {
281            av_log(avctx, AV_LOG_ERROR,
282                "Xvid: No 2-pass information loaded for second pass\n");
283            return -1;
284        }
285
286        if( strlen(avctx->stats_in) >
287              write(fd, avctx->stats_in, strlen(avctx->stats_in)) ) {
288            close(fd);
289            av_log(avctx, AV_LOG_ERROR,
290                "Xvid: Cannot write to 2-pass pipe\n");
291            return -1;
292        }
293
294        close(fd);
295        rc2pass2.filename = x->twopassfile;
296        plugins[xvid_enc_create.num_plugins].func = xvid_plugin_2pass2;
297        plugins[xvid_enc_create.num_plugins].param = &rc2pass2;
298        xvid_enc_create.num_plugins++;
299    } else if( !(xvid_flags & CODEC_FLAG_QSCALE) ) {
300        /* Single Pass Bitrate Control! */
301        memset(&single, 0, sizeof(xvid_plugin_single_t));
302        single.version = XVID_VERSION;
303        single.bitrate = avctx->bit_rate;
304
305        plugins[xvid_enc_create.num_plugins].func = xvid_plugin_single;
306        plugins[xvid_enc_create.num_plugins].param = &single;
307        xvid_enc_create.num_plugins++;
308    }
309
310    /* Luminance Masking */
311    if( 0.0 != avctx->lumi_masking ) {
312        plugins[xvid_enc_create.num_plugins].func = xvid_plugin_lumimasking;
313        plugins[xvid_enc_create.num_plugins].param = NULL;
314        xvid_enc_create.num_plugins++;
315    }
316
317    /* Frame Rate and Key Frames */
318    xvid_correct_framerate(avctx);
319    xvid_enc_create.fincr = avctx->time_base.num;
320    xvid_enc_create.fbase = avctx->time_base.den;
321    if( avctx->gop_size > 0 )
322        xvid_enc_create.max_key_interval = avctx->gop_size;
323    else
324        xvid_enc_create.max_key_interval = 240; /* Xvid's best default */
325
326    /* Quants */
327    if( xvid_flags & CODEC_FLAG_QSCALE ) x->qscale = 1;
328    else x->qscale = 0;
329
330    xvid_enc_create.min_quant[0] = avctx->qmin;
331    xvid_enc_create.min_quant[1] = avctx->qmin;
332    xvid_enc_create.min_quant[2] = avctx->qmin;
333    xvid_enc_create.max_quant[0] = avctx->qmax;
334    xvid_enc_create.max_quant[1] = avctx->qmax;
335    xvid_enc_create.max_quant[2] = avctx->qmax;
336
337    /* Quant Matrices */
338    x->intra_matrix = x->inter_matrix = NULL;
339    if( avctx->mpeg_quant )
340       x->vol_flags |= XVID_VOL_MPEGQUANT;
341    if( (avctx->intra_matrix || avctx->inter_matrix) ) {
342       x->vol_flags |= XVID_VOL_MPEGQUANT;
343
344       if( avctx->intra_matrix ) {
345           intra = avctx->intra_matrix;
346           x->intra_matrix = av_malloc(sizeof(unsigned char) * 64);
347       } else
348           intra = NULL;
349       if( avctx->inter_matrix ) {
350           inter = avctx->inter_matrix;
351           x->inter_matrix = av_malloc(sizeof(unsigned char) * 64);
352       } else
353           inter = NULL;
354
355       for( i = 0; i < 64; i++ ) {
356           if( intra )
357               x->intra_matrix[i] = (unsigned char)intra[i];
358           if( inter )
359               x->inter_matrix[i] = (unsigned char)inter[i];
360       }
361    }
362
363    /* Misc Settings */
364    xvid_enc_create.frame_drop_ratio = 0;
365    xvid_enc_create.global = 0;
366    if( xvid_flags & CODEC_FLAG_CLOSED_GOP )
367        xvid_enc_create.global |= XVID_GLOBAL_CLOSED_GOP;
368
369    /* Determines which codec mode we are operating in */
370    avctx->extradata = NULL;
371    avctx->extradata_size = 0;
372    if( xvid_flags & CODEC_FLAG_GLOBAL_HEADER ) {
373        /* In this case, we are claiming to be MPEG4 */
374        x->quicktime_format = 1;
375        avctx->codec_id = CODEC_ID_MPEG4;
376    } else {
377        /* We are claiming to be Xvid */
378        x->quicktime_format = 0;
379        if(!avctx->codec_tag)
380            avctx->codec_tag = AV_RL32("xvid");
381    }
382
383    /* Bframes */
384    xvid_enc_create.max_bframes = avctx->max_b_frames;
385    xvid_enc_create.bquant_offset = 100 * avctx->b_quant_offset;
386    xvid_enc_create.bquant_ratio = 100 * avctx->b_quant_factor;
387    if( avctx->max_b_frames > 0  && !x->quicktime_format ) xvid_enc_create.global |= XVID_GLOBAL_PACKED;
388
389    /* Create encoder context */
390    xerr = xvid_encore(NULL, XVID_ENC_CREATE, &xvid_enc_create, NULL);
391    if( xerr ) {
392        av_log(avctx, AV_LOG_ERROR, "Xvid: Could not create encoder reference\n");
393        return -1;
394    }
395
396    x->encoder_handle = xvid_enc_create.handle;
397    avctx->coded_frame = &x->encoded_picture;
398
399    return 0;
400}
401
402/**
403 * Encode a single frame.
404 *
405 * @param avctx AVCodecContext pointer to context
406 * @param frame Pointer to encoded frame buffer
407 * @param buf_size Size of encoded frame buffer
408 * @param data Pointer to AVFrame of unencoded frame
409 * @return Returns 0 on success, -1 on failure
410 */
411static int xvid_encode_frame(AVCodecContext *avctx,
412                         unsigned char *frame, int buf_size, void *data) {
413    int xerr, i;
414    char *tmp;
415    struct xvid_context *x = avctx->priv_data;
416    AVFrame *picture = data;
417    AVFrame *p = &x->encoded_picture;
418
419    xvid_enc_frame_t xvid_enc_frame;
420    xvid_enc_stats_t xvid_enc_stats;
421
422    /* Start setting up the frame */
423    memset(&xvid_enc_frame, 0, sizeof(xvid_enc_frame));
424    xvid_enc_frame.version = XVID_VERSION;
425    memset(&xvid_enc_stats, 0, sizeof(xvid_enc_stats));
426    xvid_enc_stats.version = XVID_VERSION;
427    *p = *picture;
428
429    /* Let Xvid know where to put the frame. */
430    xvid_enc_frame.bitstream = frame;
431    xvid_enc_frame.length = buf_size;
432
433    /* Initialize input image fields */
434    if( avctx->pix_fmt != PIX_FMT_YUV420P ) {
435        av_log(avctx, AV_LOG_ERROR, "Xvid: Color spaces other than 420p not supported\n");
436        return -1;
437    }
438
439    xvid_enc_frame.input.csp = XVID_CSP_PLANAR; /* YUV420P */
440
441    for( i = 0; i < 4; i++ ) {
442        xvid_enc_frame.input.plane[i] = picture->data[i];
443        xvid_enc_frame.input.stride[i] = picture->linesize[i];
444    }
445
446    /* Encoder Flags */
447    xvid_enc_frame.vop_flags = x->vop_flags;
448    xvid_enc_frame.vol_flags = x->vol_flags;
449    xvid_enc_frame.motion = x->me_flags;
450    xvid_enc_frame.type =
451        picture->pict_type == AV_PICTURE_TYPE_I ? XVID_TYPE_IVOP :
452        picture->pict_type == AV_PICTURE_TYPE_P ? XVID_TYPE_PVOP :
453        picture->pict_type == AV_PICTURE_TYPE_B ? XVID_TYPE_BVOP :
454                                          XVID_TYPE_AUTO;
455
456    /* Pixel aspect ratio setting */
457    if (avctx->sample_aspect_ratio.num < 1 || avctx->sample_aspect_ratio.num > 255 ||
458        avctx->sample_aspect_ratio.den < 1 || avctx->sample_aspect_ratio.den > 255) {
459        av_log(avctx, AV_LOG_ERROR, "Invalid pixel aspect ratio %i/%i\n",
460               avctx->sample_aspect_ratio.num, avctx->sample_aspect_ratio.den);
461        return -1;
462    }
463    xvid_enc_frame.par = XVID_PAR_EXT;
464    xvid_enc_frame.par_width  = avctx->sample_aspect_ratio.num;
465    xvid_enc_frame.par_height = avctx->sample_aspect_ratio.den;
466
467    /* Quant Setting */
468    if( x->qscale ) xvid_enc_frame.quant = picture->quality / FF_QP2LAMBDA;
469    else xvid_enc_frame.quant = 0;
470
471    /* Matrices */
472    xvid_enc_frame.quant_intra_matrix = x->intra_matrix;
473    xvid_enc_frame.quant_inter_matrix = x->inter_matrix;
474
475    /* Encode */
476    xerr = xvid_encore(x->encoder_handle, XVID_ENC_ENCODE,
477        &xvid_enc_frame, &xvid_enc_stats);
478
479    /* Two-pass log buffer swapping */
480    avctx->stats_out = NULL;
481    if( x->twopassbuffer ) {
482        tmp = x->old_twopassbuffer;
483        x->old_twopassbuffer = x->twopassbuffer;
484        x->twopassbuffer = tmp;
485        x->twopassbuffer[0] = 0;
486        if( x->old_twopassbuffer[0] != 0 ) {
487            avctx->stats_out = x->old_twopassbuffer;
488        }
489    }
490
491    if( 0 <= xerr ) {
492        p->quality = xvid_enc_stats.quant * FF_QP2LAMBDA;
493        if( xvid_enc_stats.type == XVID_TYPE_PVOP )
494            p->pict_type = AV_PICTURE_TYPE_P;
495        else if( xvid_enc_stats.type == XVID_TYPE_BVOP )
496            p->pict_type = AV_PICTURE_TYPE_B;
497        else if( xvid_enc_stats.type == XVID_TYPE_SVOP )
498            p->pict_type = AV_PICTURE_TYPE_S;
499        else
500            p->pict_type = AV_PICTURE_TYPE_I;
501        if( xvid_enc_frame.out_flags & XVID_KEYFRAME ) {
502            p->key_frame = 1;
503            if( x->quicktime_format )
504                return xvid_strip_vol_header(avctx, frame,
505                    xvid_enc_stats.hlength, xerr);
506         } else
507            p->key_frame = 0;
508
509        return xerr;
510    } else {
511        av_log(avctx, AV_LOG_ERROR, "Xvid: Encoding Error Occurred: %i\n", xerr);
512        return -1;
513    }
514}
515
516/**
517 * Destroy the private context for the encoder.
518 * All buffers are freed, and the Xvid encoder context is destroyed.
519 *
520 * @param avctx AVCodecContext pointer to context
521 * @return Returns 0, success guaranteed
522 */
523static av_cold int xvid_encode_close(AVCodecContext *avctx) {
524    struct xvid_context *x = avctx->priv_data;
525
526    xvid_encore(x->encoder_handle, XVID_ENC_DESTROY, NULL, NULL);
527
528    av_freep(&avctx->extradata);
529    if( x->twopassbuffer != NULL ) {
530        av_free(x->twopassbuffer);
531        av_free(x->old_twopassbuffer);
532    }
533    av_free(x->twopassfile);
534    av_free(x->intra_matrix);
535    av_free(x->inter_matrix);
536
537    return 0;
538}
539
540/**
541 * Routine to create a global VO/VOL header for MP4 container.
542 * What we do here is extract the header from the Xvid bitstream
543 * as it is encoded. We also strip the repeated headers from the
544 * bitstream when a global header is requested for MPEG-4 ISO
545 * compliance.
546 *
547 * @param avctx AVCodecContext pointer to context
548 * @param frame Pointer to encoded frame data
549 * @param header_len Length of header to search
550 * @param frame_len Length of encoded frame data
551 * @return Returns new length of frame data
552 */
553int xvid_strip_vol_header(AVCodecContext *avctx,
554                  unsigned char *frame,
555                  unsigned int header_len,
556                  unsigned int frame_len) {
557    int vo_len = 0, i;
558
559    for( i = 0; i < header_len - 3; i++ ) {
560        if( frame[i] == 0x00 &&
561            frame[i+1] == 0x00 &&
562            frame[i+2] == 0x01 &&
563            frame[i+3] == 0xB6 ) {
564            vo_len = i;
565            break;
566        }
567    }
568
569    if( vo_len > 0 ) {
570        /* We need to store the header, so extract it */
571        if( avctx->extradata == NULL ) {
572            avctx->extradata = av_malloc(vo_len);
573            memcpy(avctx->extradata, frame, vo_len);
574            avctx->extradata_size = vo_len;
575        }
576        /* Less dangerous now, memmove properly copies the two
577           chunks of overlapping data */
578        memmove(frame, &frame[vo_len], frame_len - vo_len);
579        return frame_len - vo_len;
580    } else
581        return frame_len;
582}
583
584/**
585 * Routine to correct a possibly erroneous framerate being fed to us.
586 * Xvid currently chokes on framerates where the ticks per frame is
587 * extremely large. This function works to correct problems in this area
588 * by estimating a new framerate and taking the simpler fraction of
589 * the two presented.
590 *
591 * @param avctx Context that contains the framerate to correct.
592 */
593void xvid_correct_framerate(AVCodecContext *avctx) {
594    int frate, fbase;
595    int est_frate, est_fbase;
596    int gcd;
597    float est_fps, fps;
598
599    frate = avctx->time_base.den;
600    fbase = avctx->time_base.num;
601
602    gcd = av_gcd(frate, fbase);
603    if( gcd > 1 ) {
604        frate /= gcd;
605        fbase /= gcd;
606    }
607
608    if( frate <= 65000 && fbase <= 65000 ) {
609        avctx->time_base.den = frate;
610        avctx->time_base.num = fbase;
611        return;
612    }
613
614    fps = (float)frate / (float)fbase;
615    est_fps = roundf(fps * 1000.0) / 1000.0;
616
617    est_frate = (int)est_fps;
618    if( est_fps > (int)est_fps ) {
619        est_frate = (est_frate + 1) * 1000;
620        est_fbase = (int)roundf((float)est_frate / est_fps);
621    } else
622        est_fbase = 1;
623
624    gcd = av_gcd(est_frate, est_fbase);
625    if( gcd > 1 ) {
626        est_frate /= gcd;
627        est_fbase /= gcd;
628    }
629
630    if( fbase > est_fbase ) {
631        avctx->time_base.den = est_frate;
632        avctx->time_base.num = est_fbase;
633        av_log(avctx, AV_LOG_DEBUG,
634            "Xvid: framerate re-estimated: %.2f, %.3f%% correction\n",
635            est_fps, (((est_fps - fps)/fps) * 100.0));
636    } else {
637        avctx->time_base.den = frate;
638        avctx->time_base.num = fbase;
639    }
640}
641
642/*
643 * Xvid 2-Pass Kludge Section
644 *
645 * Xvid's default 2-pass doesn't allow us to create data as we need to, so
646 * this section spends time replacing the first pass plugin so we can write
647 * statistic information as libavcodec requests in. We have another kludge
648 * that allows us to pass data to the second pass in Xvid without a custom
649 * rate-control plugin.
650 */
651
652/**
653 * Initialize the two-pass plugin and context.
654 *
655 * @param param Input construction parameter structure
656 * @param handle Private context handle
657 * @return Returns XVID_ERR_xxxx on failure, or 0 on success.
658 */
659static int xvid_ff_2pass_create(xvid_plg_create_t * param,
660                                void ** handle) {
661    struct xvid_ff_pass1 *x = (struct xvid_ff_pass1 *)param->param;
662    char *log = x->context->twopassbuffer;
663
664    /* Do a quick bounds check */
665    if( log == NULL )
666        return XVID_ERR_FAIL;
667
668    /* We use snprintf() */
669    /* This is because we can safely prevent a buffer overflow */
670    log[0] = 0;
671    snprintf(log, BUFFER_REMAINING(log),
672        "# avconv 2-pass log file, using xvid codec\n");
673    snprintf(BUFFER_CAT(log), BUFFER_REMAINING(log),
674        "# Do not modify. libxvidcore version: %d.%d.%d\n\n",
675        XVID_VERSION_MAJOR(XVID_VERSION),
676        XVID_VERSION_MINOR(XVID_VERSION),
677        XVID_VERSION_PATCH(XVID_VERSION));
678
679    *handle = x->context;
680    return 0;
681}
682
683/**
684 * Destroy the two-pass plugin context.
685 *
686 * @param ref Context pointer for the plugin
687 * @param param Destrooy context
688 * @return Returns 0, success guaranteed
689 */
690static int xvid_ff_2pass_destroy(struct xvid_context *ref,
691                                xvid_plg_destroy_t *param) {
692    /* Currently cannot think of anything to do on destruction */
693    /* Still, the framework should be here for reference/use */
694    if( ref->twopassbuffer != NULL )
695        ref->twopassbuffer[0] = 0;
696    return 0;
697}
698
699/**
700 * Enable fast encode mode during the first pass.
701 *
702 * @param ref Context pointer for the plugin
703 * @param param Frame data
704 * @return Returns 0, success guaranteed
705 */
706static int xvid_ff_2pass_before(struct xvid_context *ref,
707                                xvid_plg_data_t *param) {
708    int motion_remove;
709    int motion_replacements;
710    int vop_remove;
711
712    /* Nothing to do here, result is changed too much */
713    if( param->zone && param->zone->mode == XVID_ZONE_QUANT )
714        return 0;
715
716    /* We can implement a 'turbo' first pass mode here */
717    param->quant = 2;
718
719    /* Init values */
720    motion_remove = ~XVID_ME_CHROMA_PVOP &
721                    ~XVID_ME_CHROMA_BVOP &
722                    ~XVID_ME_EXTSEARCH16 &
723                    ~XVID_ME_ADVANCEDDIAMOND16;
724    motion_replacements = XVID_ME_FAST_MODEINTERPOLATE |
725                          XVID_ME_SKIP_DELTASEARCH |
726                          XVID_ME_FASTREFINE16 |
727                          XVID_ME_BFRAME_EARLYSTOP;
728    vop_remove = ~XVID_VOP_MODEDECISION_RD &
729                 ~XVID_VOP_FAST_MODEDECISION_RD &
730                 ~XVID_VOP_TRELLISQUANT &
731                 ~XVID_VOP_INTER4V &
732                 ~XVID_VOP_HQACPRED;
733
734    param->vol_flags &= ~XVID_VOL_GMC;
735    param->vop_flags &= vop_remove;
736    param->motion_flags &= motion_remove;
737    param->motion_flags |= motion_replacements;
738
739    return 0;
740}
741
742/**
743 * Capture statistic data and write it during first pass.
744 *
745 * @param ref Context pointer for the plugin
746 * @param param Statistic data
747 * @return Returns XVID_ERR_xxxx on failure, or 0 on success
748 */
749static int xvid_ff_2pass_after(struct xvid_context *ref,
750                                xvid_plg_data_t *param) {
751    char *log = ref->twopassbuffer;
752    const char *frame_types = " ipbs";
753    char frame_type;
754
755    /* Quick bounds check */
756    if( log == NULL )
757        return XVID_ERR_FAIL;
758
759    /* Convert the type given to us into a character */
760    if( param->type < 5 && param->type > 0 ) {
761        frame_type = frame_types[param->type];
762    } else {
763        return XVID_ERR_FAIL;
764    }
765
766    snprintf(BUFFER_CAT(log), BUFFER_REMAINING(log),
767        "%c %d %d %d %d %d %d\n",
768        frame_type, param->stats.quant, param->stats.kblks, param->stats.mblks,
769        param->stats.ublks, param->stats.length, param->stats.hlength);
770
771    return 0;
772}
773
774/**
775 * Dispatch function for our custom plugin.
776 * This handles the dispatch for the Xvid plugin. It passes data
777 * on to other functions for actual processing.
778 *
779 * @param ref Context pointer for the plugin
780 * @param cmd The task given for us to complete
781 * @param p1 First parameter (varies)
782 * @param p2 Second parameter (varies)
783 * @return Returns XVID_ERR_xxxx on failure, or 0 on success
784 */
785int xvid_ff_2pass(void *ref, int cmd, void *p1, void *p2) {
786    switch( cmd ) {
787        case XVID_PLG_INFO:
788        case XVID_PLG_FRAME:
789            return 0;
790
791        case XVID_PLG_BEFORE:
792            return xvid_ff_2pass_before(ref, p1);
793
794        case XVID_PLG_CREATE:
795            return xvid_ff_2pass_create(p1, p2);
796
797        case XVID_PLG_AFTER:
798            return xvid_ff_2pass_after(ref, p1);
799
800        case XVID_PLG_DESTROY:
801            return xvid_ff_2pass_destroy(ref, p1);
802
803        default:
804            return XVID_ERR_FAIL;
805    }
806}
807
808/**
809 * Xvid codec definition for libavcodec.
810 */
811AVCodec ff_libxvid_encoder = {
812    .name           = "libxvid",
813    .type           = AVMEDIA_TYPE_VIDEO,
814    .id             = CODEC_ID_MPEG4,
815    .priv_data_size = sizeof(struct xvid_context),
816    .init           = xvid_encode_init,
817    .encode         = xvid_encode_frame,
818    .close          = xvid_encode_close,
819    .pix_fmts= (const enum PixelFormat[]){PIX_FMT_YUV420P, PIX_FMT_NONE},
820    .long_name= NULL_IF_CONFIG_SMALL("libxvidcore MPEG-4 part 2"),
821};
822
823#endif /* CONFIG_LIBXVID_ENCODER */
824