avisynth.c 21.1 KB
Newer Older
1
/*
d s's avatar
d s committed
2 3
 * AviSynth/AvxSynth support
 * Copyright (c) 2012 AvxSynth Team.
4
 *
5
 * This file is part of Libav.
6
 *
7
 * Libav is free software; you can redistribute it and/or
8 9
 * modify it under the terms of the GNU Lesser General Public
 * 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 14 15 16 17
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * 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 20 21
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

22
#include "libavutil/internal.h"
d s's avatar
d s committed
23
#include "libavcodec/internal.h"
24
#include "avformat.h"
25
#include "internal.h"
26
#include "config.h"
d s's avatar
d s committed
27 28 29 30

/* Enable function pointer definitions for runtime loading. */
#define AVSC_NO_DECLSPEC

31
/* Platform-specific directives for AviSynth vs AvxSynth. */
d s's avatar
d s committed
32 33 34 35 36 37 38 39 40
#ifdef _WIN32
  #include <windows.h>
  #undef EXTERN_C
  #include <avisynth/avisynth_c.h>
  #define AVISYNTH_LIB "avisynth"
  #define USING_AVISYNTH
#else
  #include <dlfcn.h>
  #include <avxsynth/avxsynth_c.h>
41 42
  #define AVISYNTH_NAME "libavxsynth"
  #define AVISYNTH_LIB AVISYNTH_NAME SLIBSUF
d s's avatar
d s committed
43

44
  #define LoadLibrary(x) dlopen(x, RTLD_NOW | RTLD_LOCAL)
d s's avatar
d s committed
45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
  #define GetProcAddress dlsym
  #define FreeLibrary dlclose
#endif

typedef struct AviSynthLibrary {
    void *library;
#define AVSC_DECLARE_FUNC(name) name ## _func name
    AVSC_DECLARE_FUNC(avs_bit_blt);
    AVSC_DECLARE_FUNC(avs_clip_get_error);
    AVSC_DECLARE_FUNC(avs_create_script_environment);
    AVSC_DECLARE_FUNC(avs_delete_script_environment);
    AVSC_DECLARE_FUNC(avs_get_audio);
    AVSC_DECLARE_FUNC(avs_get_error);
    AVSC_DECLARE_FUNC(avs_get_frame);
    AVSC_DECLARE_FUNC(avs_get_version);
    AVSC_DECLARE_FUNC(avs_get_video_info);
    AVSC_DECLARE_FUNC(avs_invoke);
    AVSC_DECLARE_FUNC(avs_release_clip);
    AVSC_DECLARE_FUNC(avs_release_value);
    AVSC_DECLARE_FUNC(avs_release_video_frame);
    AVSC_DECLARE_FUNC(avs_take_clip);
66 67 68 69 70 71 72 73 74 75 76
#ifdef USING_AVISYNTH
    AVSC_DECLARE_FUNC(avs_bits_per_pixel);
    AVSC_DECLARE_FUNC(avs_get_height_p);
    AVSC_DECLARE_FUNC(avs_get_pitch_p);
    AVSC_DECLARE_FUNC(avs_get_read_ptr_p);
    AVSC_DECLARE_FUNC(avs_get_row_size_p);
    AVSC_DECLARE_FUNC(avs_is_yv24);
    AVSC_DECLARE_FUNC(avs_is_yv16);
    AVSC_DECLARE_FUNC(avs_is_yv411);
    AVSC_DECLARE_FUNC(avs_is_y8);
#endif
d s's avatar
d s committed
77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96
#undef AVSC_DECLARE_FUNC
} AviSynthLibrary;

typedef struct AviSynthContext {
    AVS_ScriptEnvironment *env;
    AVS_Clip *clip;
    const AVS_VideoInfo *vi;

    /* avisynth_read_packet_video() iterates over this. */
    int n_planes;
    const int *planes;

    int curr_stream;
    int curr_frame;
    int64_t curr_sample;

    int error;

    /* Linked list pointers. */
    struct AviSynthContext *next;
Diego Biurrun's avatar
Diego Biurrun committed
97
} AviSynthContext;
98

d s's avatar
d s committed
99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139
static const int avs_planes_packed[1] = { 0 };
static const int avs_planes_grey[1]   = { AVS_PLANAR_Y };
static const int avs_planes_yuv[3]    = { AVS_PLANAR_Y, AVS_PLANAR_U,
                                          AVS_PLANAR_V };

/* A conflict between C++ global objects, atexit, and dynamic loading requires
 * us to register our own atexit handler to prevent double freeing. */
static AviSynthLibrary avs_library;
static int avs_atexit_called        = 0;

/* Linked list of AviSynthContexts. An atexit handler destroys this list. */
static AviSynthContext *avs_ctx_list = NULL;

static av_cold void avisynth_atexit_handler(void);

static av_cold int avisynth_load_library(void)
{
    avs_library.library = LoadLibrary(AVISYNTH_LIB);
    if (!avs_library.library)
        return AVERROR_UNKNOWN;

#define LOAD_AVS_FUNC(name, continue_on_fail)                          \
        avs_library.name =                                             \
            (void *)GetProcAddress(avs_library.library, #name);        \
        if (!continue_on_fail && !avs_library.name)                    \
            goto fail;

    LOAD_AVS_FUNC(avs_bit_blt, 0);
    LOAD_AVS_FUNC(avs_clip_get_error, 0);
    LOAD_AVS_FUNC(avs_create_script_environment, 0);
    LOAD_AVS_FUNC(avs_delete_script_environment, 0);
    LOAD_AVS_FUNC(avs_get_audio, 0);
    LOAD_AVS_FUNC(avs_get_error, 1); // New to AviSynth 2.6
    LOAD_AVS_FUNC(avs_get_frame, 0);
    LOAD_AVS_FUNC(avs_get_version, 0);
    LOAD_AVS_FUNC(avs_get_video_info, 0);
    LOAD_AVS_FUNC(avs_invoke, 0);
    LOAD_AVS_FUNC(avs_release_clip, 0);
    LOAD_AVS_FUNC(avs_release_value, 0);
    LOAD_AVS_FUNC(avs_release_video_frame, 0);
    LOAD_AVS_FUNC(avs_take_clip, 0);
140
#ifdef USING_AVISYNTH
141 142 143 144 145 146 147 148 149
    LOAD_AVS_FUNC(avs_bits_per_pixel, 1);
    LOAD_AVS_FUNC(avs_get_height_p, 1);
    LOAD_AVS_FUNC(avs_get_pitch_p, 1);
    LOAD_AVS_FUNC(avs_get_read_ptr_p, 1);
    LOAD_AVS_FUNC(avs_get_row_size_p, 1);
    LOAD_AVS_FUNC(avs_is_yv24, 1);
    LOAD_AVS_FUNC(avs_is_yv16, 1);
    LOAD_AVS_FUNC(avs_is_yv411, 1);
    LOAD_AVS_FUNC(avs_is_y8, 1);
150
#endif
d s's avatar
d s committed
151 152 153 154 155 156 157 158 159 160 161 162 163 164
#undef LOAD_AVS_FUNC

    atexit(avisynth_atexit_handler);
    return 0;

fail:
    FreeLibrary(avs_library.library);
    return AVERROR_UNKNOWN;
}

/* Note that avisynth_context_create and avisynth_context_destroy
 * do not allocate or free the actual context! That is taken care of
 * by libavformat. */
static av_cold int avisynth_context_create(AVFormatContext *s)
165
{
166
    AviSynthContext *avs = s->priv_data;
d s's avatar
d s committed
167 168 169 170 171 172 173 174 175 176 177 178
    int ret;

    if (!avs_library.library)
        if (ret = avisynth_load_library())
            return ret;

    avs->env = avs_library.avs_create_script_environment(3);
    if (avs_library.avs_get_error) {
        const char *error = avs_library.avs_get_error(avs->env);
        if (error) {
            av_log(s, AV_LOG_ERROR, "%s\n", error);
            return AVERROR_UNKNOWN;
179 180 181
        }
    }

d s's avatar
d s committed
182 183 184 185 186 187 188
    if (!avs_ctx_list) {
        avs_ctx_list = avs;
    } else {
        avs->next    = avs_ctx_list;
        avs_ctx_list = avs;
    }

189
    return 0;
190 191
}

d s's avatar
d s committed
192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316
static av_cold void avisynth_context_destroy(AviSynthContext *avs)
{
    if (avs_atexit_called)
        return;

    if (avs == avs_ctx_list) {
        avs_ctx_list = avs->next;
    } else {
        AviSynthContext *prev = avs_ctx_list;
        while (prev->next != avs)
            prev = prev->next;
        prev->next = avs->next;
    }

    if (avs->clip) {
        avs_library.avs_release_clip(avs->clip);
        avs->clip = NULL;
    }
    if (avs->env) {
        avs_library.avs_delete_script_environment(avs->env);
        avs->env = NULL;
    }
}

static av_cold void avisynth_atexit_handler(void)
{
    AviSynthContext *avs = avs_ctx_list;

    while (avs) {
        AviSynthContext *next = avs->next;
        avisynth_context_destroy(avs);
        avs = next;
    }
    FreeLibrary(avs_library.library);

    avs_atexit_called = 1;
}

/* Create AVStream from audio and video data. */
static int avisynth_create_stream_video(AVFormatContext *s, AVStream *st)
{
    AviSynthContext *avs = s->priv_data;
    int planar = 0; // 0: packed, 1: YUV, 2: Y8

    st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
    st->codec->codec_id   = AV_CODEC_ID_RAWVIDEO;
    st->codec->width      = avs->vi->width;
    st->codec->height     = avs->vi->height;

    st->time_base         = (AVRational) { avs->vi->fps_denominator,
                                           avs->vi->fps_numerator };
    st->avg_frame_rate    = (AVRational) { avs->vi->fps_numerator,
                                           avs->vi->fps_denominator };
    st->start_time        = 0;
    st->duration          = avs->vi->num_frames;
    st->nb_frames         = avs->vi->num_frames;

    switch (avs->vi->pixel_type) {
#ifdef USING_AVISYNTH
    case AVS_CS_YV24:
        st->codec->pix_fmt = AV_PIX_FMT_YUV444P;
        planar             = 1;
        break;
    case AVS_CS_YV16:
        st->codec->pix_fmt = AV_PIX_FMT_YUV422P;
        planar             = 1;
        break;
    case AVS_CS_YV411:
        st->codec->pix_fmt = AV_PIX_FMT_YUV411P;
        planar             = 1;
        break;
    case AVS_CS_Y8:
        st->codec->pix_fmt = AV_PIX_FMT_GRAY8;
        planar             = 2;
        break;
#endif
    case AVS_CS_BGR24:
        st->codec->pix_fmt = AV_PIX_FMT_BGR24;
        break;
    case AVS_CS_BGR32:
        st->codec->pix_fmt = AV_PIX_FMT_RGB32;
        break;
    case AVS_CS_YUY2:
        st->codec->pix_fmt = AV_PIX_FMT_YUYV422;
        break;
    case AVS_CS_YV12:
        st->codec->pix_fmt = AV_PIX_FMT_YUV420P;
        planar             = 1;
        break;
    case AVS_CS_I420: // Is this even used anywhere?
        st->codec->pix_fmt = AV_PIX_FMT_YUV420P;
        planar             = 1;
        break;
    default:
        av_log(s, AV_LOG_ERROR,
               "unknown AviSynth colorspace %d\n", avs->vi->pixel_type);
        avs->error = 1;
        return AVERROR_UNKNOWN;
    }

    switch (planar) {
    case 2: // Y8
        avs->n_planes = 1;
        avs->planes   = avs_planes_grey;
        break;
    case 1: // YUV
        avs->n_planes = 3;
        avs->planes   = avs_planes_yuv;
        break;
    default:
        avs->n_planes = 1;
        avs->planes   = avs_planes_packed;
    }
    return 0;
}

static int avisynth_create_stream_audio(AVFormatContext *s, AVStream *st)
{
    AviSynthContext *avs = s->priv_data;

    st->codec->codec_type  = AVMEDIA_TYPE_AUDIO;
    st->codec->sample_rate = avs->vi->audio_samples_per_second;
    st->codec->channels    = avs->vi->nchannels;
    st->time_base          = (AVRational) { 1,
                                            avs->vi->audio_samples_per_second };
317
    st->duration           = avs->vi->num_audio_samples;
d s's avatar
d s committed
318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370

    switch (avs->vi->sample_type) {
    case AVS_SAMPLE_INT8:
        st->codec->codec_id = AV_CODEC_ID_PCM_U8;
        break;
    case AVS_SAMPLE_INT16:
        st->codec->codec_id = AV_CODEC_ID_PCM_S16LE;
        break;
    case AVS_SAMPLE_INT24:
        st->codec->codec_id = AV_CODEC_ID_PCM_S24LE;
        break;
    case AVS_SAMPLE_INT32:
        st->codec->codec_id = AV_CODEC_ID_PCM_S32LE;
        break;
    case AVS_SAMPLE_FLOAT:
        st->codec->codec_id = AV_CODEC_ID_PCM_F32LE;
        break;
    default:
        av_log(s, AV_LOG_ERROR,
               "unknown AviSynth sample type %d\n", avs->vi->sample_type);
        avs->error = 1;
        return AVERROR_UNKNOWN;
    }
    return 0;
}

static int avisynth_create_stream(AVFormatContext *s)
{
    AviSynthContext *avs = s->priv_data;
    AVStream *st;
    int ret;
    int id = 0;

    if (avs_has_video(avs->vi)) {
        st = avformat_new_stream(s, NULL);
        if (!st)
            return AVERROR_UNKNOWN;
        st->id = id++;
        if (ret = avisynth_create_stream_video(s, st))
            return ret;
    }
    if (avs_has_audio(avs->vi)) {
        st = avformat_new_stream(s, NULL);
        if (!st)
            return AVERROR_UNKNOWN;
        st->id = id++;
        if (ret = avisynth_create_stream_audio(s, st))
            return ret;
    }
    return 0;
}

static int avisynth_open_file(AVFormatContext *s)
371
{
372
    AviSynthContext *avs = s->priv_data;
d s's avatar
d s committed
373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402
    AVS_Value arg, val;
    int ret;
#ifdef USING_AVISYNTH
    char filename_ansi[MAX_PATH * 4];
    wchar_t filename_wc[MAX_PATH * 4];
#endif

    if (ret = avisynth_context_create(s))
        return ret;

#ifdef USING_AVISYNTH
    /* Convert UTF-8 to ANSI code page */
    MultiByteToWideChar(CP_UTF8, 0, s->filename, -1, filename_wc, MAX_PATH * 4);
    WideCharToMultiByte(CP_THREAD_ACP, 0, filename_wc, -1, filename_ansi,
                        MAX_PATH * 4, NULL, NULL);
    arg = avs_new_value_string(filename_ansi);
#else
    arg = avs_new_value_string(s->filename);
#endif
    val = avs_library.avs_invoke(avs->env, "Import", arg, 0);
    if (avs_is_error(val)) {
        av_log(s, AV_LOG_ERROR, "%s\n", avs_as_error(val));
        ret = AVERROR_UNKNOWN;
        goto fail;
    }
    if (!avs_is_clip(val)) {
        av_log(s, AV_LOG_ERROR, "AviSynth script did not return a clip\n");
        ret = AVERROR_UNKNOWN;
        goto fail;
    }
403

d s's avatar
d s committed
404 405
    avs->clip = avs_library.avs_take_clip(val, avs->env);
    avs->vi   = avs_library.avs_get_video_info(avs->clip);
406

d s's avatar
d s committed
407
#ifdef USING_AVISYNTH
408 409 410 411
    /* On Windows, libav supports AviSynth interface version 6 or higher.
     * This includes AviSynth 2.6 RC1 or higher, and AviSynth+ r1718 or higher,
     * and excludes 2.5 and the 2.6 alphas. Since AvxSynth identifies itself
     * as interface version 3 like 2.5.8, this needs to be special-cased. */
d s's avatar
d s committed
412

413
    if (avs_library.avs_get_version(avs->clip) < 6) {
d s's avatar
d s committed
414
        av_log(s, AV_LOG_ERROR,
415
               "AviSynth version is too old. Please upgrade to either AviSynth 2.6 >= RC1 or AviSynth+ >= r1718.\n");
d s's avatar
d s committed
416 417 418 419
        ret = AVERROR_UNKNOWN;
        goto fail;
    }
#endif
420

d s's avatar
d s committed
421 422 423 424 425 426 427
    /* Release the AVS_Value as it will go out of scope. */
    avs_library.avs_release_value(val);

    if (ret = avisynth_create_stream(s))
        goto fail;

    return 0;
428

d s's avatar
d s committed
429 430 431 432
fail:
    avisynth_context_destroy(avs);
    return ret;
}
433

d s's avatar
d s committed
434 435 436 437
static void avisynth_next_stream(AVFormatContext *s, AVStream **st,
                                 AVPacket *pkt, int *discard)
{
    AviSynthContext *avs = s->priv_data;
438

439
    avs->curr_stream++;
d s's avatar
d s committed
440
    avs->curr_stream %= s->nb_streams;
441

442
    *st = s->streams[avs->curr_stream];
d s's avatar
d s committed
443 444 445 446
    if ((*st)->discard == AVDISCARD_ALL)
        *discard = 1;
    else
        *discard = 0;
447

d s's avatar
d s committed
448
    return;
449 450
}

d s's avatar
d s committed
451 452 453
/* Copy AviSynth clip data into an AVPacket. */
static int avisynth_read_packet_video(AVFormatContext *s, AVPacket *pkt,
                                      int discard)
454
{
455
    AviSynthContext *avs = s->priv_data;
d s's avatar
d s committed
456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474
    AVS_VideoFrame *frame;
    unsigned char *dst_p;
    const unsigned char *src_p;
    int n, i, plane, rowsize, planeheight, pitch, bits;
    const char *error;

    if (avs->curr_frame >= avs->vi->num_frames)
        return AVERROR_EOF;

    /* This must happen even if the stream is discarded to prevent desync. */
    n = avs->curr_frame++;
    if (discard)
        return 0;

#ifdef USING_AVISYNTH
    /* Define the bpp values for the new AviSynth 2.6 colorspaces.
     * Since AvxSynth doesn't have these functions, special-case
     * it in order to avoid implicit declaration errors. */

475
    if (avs_library.avs_is_yv24(avs->vi))
d s's avatar
d s committed
476
        bits = 24;
477
    else if (avs_library.avs_is_yv16(avs->vi))
d s's avatar
d s committed
478
        bits = 16;
479
    else if (avs_library.avs_is_yv411(avs->vi))
d s's avatar
d s committed
480
        bits = 12;
481
    else if (avs_library.avs_is_y8(avs->vi))
d s's avatar
d s committed
482 483
        bits = 8;
    else
484 485 486
        bits = avs_library.avs_bits_per_pixel(avs->vi);
#else
    bits = avs_bits_per_pixel(avs->vi);
d s's avatar
d s committed
487 488 489 490 491 492 493 494 495 496 497 498
#endif

    /* Without the cast to int64_t, calculation overflows at about 9k x 9k
     * resolution. */
    pkt->size = (((int64_t)avs->vi->width *
                  (int64_t)avs->vi->height) * bits) / 8;
    if (!pkt->size)
        return AVERROR_UNKNOWN;

    if (av_new_packet(pkt, pkt->size) < 0)
        return AVERROR(ENOMEM);

499 500 501 502 503
    pkt->pts      = n;
    pkt->dts      = n;
    pkt->duration = 1;
    pkt->stream_index = avs->curr_stream;

d s's avatar
d s committed
504 505 506 507 508 509 510 511
    frame = avs_library.avs_get_frame(avs->clip, n);
    error = avs_library.avs_clip_get_error(avs->clip);
    if (error) {
        av_log(s, AV_LOG_ERROR, "%s\n", error);
        avs->error = 1;
        av_packet_unref(pkt);
        return AVERROR_UNKNOWN;
    }
512

d s's avatar
d s committed
513 514 515
    dst_p = pkt->data;
    for (i = 0; i < avs->n_planes; i++) {
        plane = avs->planes[i];
516 517 518 519 520 521 522
#ifdef USING_AVISYNTH
        src_p = avs_library.avs_get_read_ptr_p(frame, plane);
        pitch = avs_library.avs_get_pitch_p(frame, plane);

        rowsize     = avs_library.avs_get_row_size_p(frame, plane);
        planeheight = avs_library.avs_get_height_p(frame, plane);
#else
d s's avatar
d s committed
523 524 525 526 527
        src_p = avs_get_read_ptr_p(frame, plane);
        pitch = avs_get_pitch_p(frame, plane);

        rowsize     = avs_get_row_size_p(frame, plane);
        planeheight = avs_get_height_p(frame, plane);
528
#endif
d s's avatar
d s committed
529 530 531 532 533 534

        /* Flip RGB video. */
        if (avs_is_rgb24(avs->vi) || avs_is_rgb(avs->vi)) {
            src_p = src_p + (planeheight - 1) * pitch;
            pitch = -pitch;
        }
535

d s's avatar
d s committed
536 537 538 539 540 541
        avs_library.avs_bit_blt(avs->env, dst_p, rowsize, src_p, pitch,
                                 rowsize, planeheight);
        dst_p += rowsize * planeheight;
    }

    avs_library.avs_release_video_frame(frame);
542
    return 0;
543 544
}

d s's avatar
d s committed
545 546
static int avisynth_read_packet_audio(AVFormatContext *s, AVPacket *pkt,
                                      int discard)
547
{
548
    AviSynthContext *avs = s->priv_data;
d s's avatar
d s committed
549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595
    AVRational fps, samplerate;
    int samples;
    int64_t n;
    const char *error;

    if (avs->curr_sample >= avs->vi->num_audio_samples)
        return AVERROR_EOF;

    fps.num        = avs->vi->fps_numerator;
    fps.den        = avs->vi->fps_denominator;
    samplerate.num = avs->vi->audio_samples_per_second;
    samplerate.den = 1;

    if (avs_has_video(avs->vi)) {
        if (avs->curr_frame < avs->vi->num_frames)
            samples = av_rescale_q(avs->curr_frame, samplerate, fps) -
                      avs->curr_sample;
        else
            samples = av_rescale_q(1, samplerate, fps);
    } else {
        samples = 1000;
    }

    /* After seeking, audio may catch up with video. */
    if (samples <= 0) {
        pkt->size = 0;
        pkt->data = NULL;
        return 0;
    }

    if (avs->curr_sample + samples > avs->vi->num_audio_samples)
        samples = avs->vi->num_audio_samples - avs->curr_sample;

    /* This must happen even if the stream is discarded to prevent desync. */
    n                 = avs->curr_sample;
    avs->curr_sample += samples;
    if (discard)
        return 0;

    pkt->size = avs_bytes_per_channel_sample(avs->vi) *
                samples * avs->vi->nchannels;
    if (!pkt->size)
        return AVERROR_UNKNOWN;

    if (av_new_packet(pkt, pkt->size) < 0)
        return AVERROR(ENOMEM);

596 597 598 599 600
    pkt->pts      = n;
    pkt->dts      = n;
    pkt->duration = samples;
    pkt->stream_index = avs->curr_stream;

d s's avatar
d s committed
601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618
    avs_library.avs_get_audio(avs->clip, pkt->data, n, samples);
    error = avs_library.avs_clip_get_error(avs->clip);
    if (error) {
        av_log(s, AV_LOG_ERROR, "%s\n", error);
        avs->error = 1;
        av_packet_unref(pkt);
        return AVERROR_UNKNOWN;
    }
    return 0;
}

static av_cold int avisynth_read_header(AVFormatContext *s)
{
    int ret;

    // Calling library must implement a lock for thread-safe opens.
    if (ret = avpriv_lock_avformat())
        return ret;
619

d s's avatar
d s committed
620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703
    if (ret = avisynth_open_file(s)) {
        avpriv_unlock_avformat();
        return ret;
    }

    avpriv_unlock_avformat();
    return 0;
}

static int avisynth_read_packet(AVFormatContext *s, AVPacket *pkt)
{
    AviSynthContext *avs = s->priv_data;
    AVStream *st;
    int discard = 0;
    int ret;

    if (avs->error)
        return AVERROR_UNKNOWN;

    /* If either stream reaches EOF, try to read the other one before
     * giving up. */
    avisynth_next_stream(s, &st, pkt, &discard);
    if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
        ret = avisynth_read_packet_video(s, pkt, discard);
        if (ret == AVERROR_EOF && avs_has_audio(avs->vi)) {
            avisynth_next_stream(s, &st, pkt, &discard);
            return avisynth_read_packet_audio(s, pkt, discard);
        }
    } else {
        ret = avisynth_read_packet_audio(s, pkt, discard);
        if (ret == AVERROR_EOF && avs_has_video(avs->vi)) {
            avisynth_next_stream(s, &st, pkt, &discard);
            return avisynth_read_packet_video(s, pkt, discard);
        }
    }

    return ret;
}

static av_cold int avisynth_read_close(AVFormatContext *s)
{
    if (avpriv_lock_avformat())
        return AVERROR_UNKNOWN;

    avisynth_context_destroy(s->priv_data);
    avpriv_unlock_avformat();
    return 0;
}

static int avisynth_read_seek(AVFormatContext *s, int stream_index,
                              int64_t timestamp, int flags)
{
    AviSynthContext *avs = s->priv_data;
    AVStream *st;
    AVRational fps, samplerate;

    if (avs->error)
        return AVERROR_UNKNOWN;

    fps        = (AVRational) { avs->vi->fps_numerator,
                                avs->vi->fps_denominator };
    samplerate = (AVRational) { avs->vi->audio_samples_per_second, 1 };

    st = s->streams[stream_index];
    if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
        /* AviSynth frame counts are signed int. */
        if ((timestamp >= avs->vi->num_frames) ||
            (timestamp > INT_MAX)              ||
            (timestamp < 0))
            return AVERROR_EOF;
        avs->curr_frame = timestamp;
        if (avs_has_audio(avs->vi))
            avs->curr_sample = av_rescale_q(timestamp, samplerate, fps);
    } else {
        if ((timestamp >= avs->vi->num_audio_samples) || (timestamp < 0))
            return AVERROR_EOF;
        /* Force frame granularity for seeking. */
        if (avs_has_video(avs->vi)) {
            avs->curr_frame  = av_rescale_q(timestamp, fps, samplerate);
            avs->curr_sample = av_rescale_q(avs->curr_frame, samplerate, fps);
        } else {
            avs->curr_sample = timestamp;
        }
    }
704

705
    return 0;
706 707
}

708
AVInputFormat ff_avisynth_demuxer = {
709
    .name           = "avisynth",
d s's avatar
d s committed
710
    .long_name      = NULL_IF_CONFIG_SMALL("AviSynth script"),
Diego Biurrun's avatar
Diego Biurrun committed
711
    .priv_data_size = sizeof(AviSynthContext),
712 713 714 715 716
    .read_header    = avisynth_read_header,
    .read_packet    = avisynth_read_packet,
    .read_close     = avisynth_read_close,
    .read_seek      = avisynth_read_seek,
    .extensions     = "avs",
717
};