yading@11: /*
yading@11:  * Avi/AvxSynth support
yading@11:  * Copyright (c) 2012 AvxSynth Team.
yading@11:  *
yading@11:  * This file is part of FFmpeg
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: #include "avformat.h"
yading@11: #include "internal.h"
yading@11: #include "libavcodec/internal.h"
yading@11: 
yading@11: // Enable function pointer definitions for runtime loading.
yading@11: #define AVSC_NO_DECLSPEC
yading@11: 
yading@11: // Shut up ffmpeg error messages.
yading@11: // avisynth_c.h contains inline functions that call these functions.
yading@11: #undef malloc
yading@11: #undef free
yading@11: #undef printf
yading@11: 
yading@11: // Platform-specific directives for AviSynth vs AvxSynth.
yading@11: #ifdef _WIN32
yading@11:   #include <windows.h>
yading@11:   #undef EXTERN_C
yading@11:   #include "compat/avisynth/avisynth_c.h"
yading@11:   #define AVISYNTH_LIB "avisynth"
yading@11: #else
yading@11:   #include <dlfcn.h>
yading@11:   #include "compat/avisynth/avxsynth_c.h"
yading@11:    #if defined (__APPLE__)
yading@11:      #define AVISYNTH_LIB "libavxsynth.dylib"
yading@11:    #else
yading@11:      #define AVISYNTH_LIB "libavxsynth.so"
yading@11:    #endif
yading@11: 
yading@11:   #define LoadLibrary(x) dlopen(x, RTLD_NOW | RTLD_GLOBAL)
yading@11:   #define GetProcAddress dlsym
yading@11:   #define FreeLibrary dlclose
yading@11: #endif
yading@11: 
yading@11: // AvxSynth doesn't have these colorspaces, so disable them
yading@11: #ifndef _WIN32
yading@11: #define avs_is_yv24(vi) 0
yading@11: #define avs_is_yv16(vi) 0
yading@11: #define avs_is_yv411(vi) 0
yading@11: #define avs_is_y8(vi) 0
yading@11: #endif
yading@11: 
yading@11: typedef struct {
yading@11:     void *library;
yading@11: #define AVSC_DECLARE_FUNC(name) name##_func name
yading@11:     AVSC_DECLARE_FUNC(avs_create_script_environment);
yading@11:     AVSC_DECLARE_FUNC(avs_delete_script_environment);
yading@11:     AVSC_DECLARE_FUNC(avs_get_error);
yading@11:     AVSC_DECLARE_FUNC(avs_clip_get_error);
yading@11:     AVSC_DECLARE_FUNC(avs_invoke);
yading@11:     AVSC_DECLARE_FUNC(avs_release_value);
yading@11:     AVSC_DECLARE_FUNC(avs_get_video_info);
yading@11:     AVSC_DECLARE_FUNC(avs_take_clip);
yading@11:     AVSC_DECLARE_FUNC(avs_release_clip);
yading@11:     AVSC_DECLARE_FUNC(avs_bit_blt);
yading@11:     AVSC_DECLARE_FUNC(avs_get_audio);
yading@11:     AVSC_DECLARE_FUNC(avs_get_frame);
yading@11:     AVSC_DECLARE_FUNC(avs_release_video_frame);
yading@11: #undef AVSC_DECLARE_FUNC
yading@11: } AviSynthLibrary;
yading@11: 
yading@11: struct AviSynthContext {
yading@11:     AVS_ScriptEnvironment *env;
yading@11:     AVS_Clip *clip;
yading@11:     const AVS_VideoInfo *vi;
yading@11: 
yading@11:     // avisynth_read_packet_video() iterates over this.
yading@11:     int n_planes;
yading@11:     const int *planes;
yading@11: 
yading@11:     int curr_stream;
yading@11:     int curr_frame;
yading@11:     int64_t curr_sample;
yading@11: 
yading@11:     int error;
yading@11: 
yading@11:     // Linked list pointers.
yading@11:     struct AviSynthContext *next;
yading@11: };
yading@11: typedef struct AviSynthContext AviSynthContext;
yading@11: 
yading@11: static const int avs_planes_packed[1] = {0};
yading@11: static const int avs_planes_grey[1] = {AVS_PLANAR_Y};
yading@11: static const int avs_planes_yuv[3] = {AVS_PLANAR_Y, AVS_PLANAR_U, AVS_PLANAR_V};
yading@11: 
yading@11: // A conflict between C++ global objects, atexit, and dynamic loading requires
yading@11: // us to register our own atexit handler to prevent double freeing.
yading@11: static AviSynthLibrary *avs_library = NULL;
yading@11: static int avs_atexit_called = 0;
yading@11: 
yading@11: // Linked list of AviSynthContexts. An atexit handler destroys this list.
yading@11: static AviSynthContext *avs_ctx_list = NULL;
yading@11: 
yading@11: static av_cold void avisynth_atexit_handler(void);
yading@11: 
yading@11: static av_cold int avisynth_load_library(void) {
yading@11:     avs_library = av_mallocz(sizeof(AviSynthLibrary));
yading@11:     if (!avs_library)
yading@11:         return AVERROR_UNKNOWN;
yading@11: 
yading@11:     avs_library->library = LoadLibrary(AVISYNTH_LIB);
yading@11:     if (!avs_library->library)
yading@11:         goto init_fail;
yading@11: 
yading@11: #define LOAD_AVS_FUNC(name, continue_on_fail) \
yading@11: { \
yading@11:     avs_library->name = (void*)GetProcAddress(avs_library->library, #name); \
yading@11:     if(!continue_on_fail && !avs_library->name) \
yading@11:         goto fail; \
yading@11: }
yading@11:     LOAD_AVS_FUNC(avs_create_script_environment, 0);
yading@11:     LOAD_AVS_FUNC(avs_delete_script_environment, 0);
yading@11:     LOAD_AVS_FUNC(avs_get_error, 1); // New to AviSynth 2.6
yading@11:     LOAD_AVS_FUNC(avs_clip_get_error, 0);
yading@11:     LOAD_AVS_FUNC(avs_invoke, 0);
yading@11:     LOAD_AVS_FUNC(avs_release_value, 0);
yading@11:     LOAD_AVS_FUNC(avs_get_video_info, 0);
yading@11:     LOAD_AVS_FUNC(avs_take_clip, 0);
yading@11:     LOAD_AVS_FUNC(avs_release_clip, 0);
yading@11:     LOAD_AVS_FUNC(avs_bit_blt, 0);
yading@11:     LOAD_AVS_FUNC(avs_get_audio, 0);
yading@11:     LOAD_AVS_FUNC(avs_get_frame, 0);
yading@11:     LOAD_AVS_FUNC(avs_release_video_frame, 0);
yading@11: #undef LOAD_AVS_FUNC
yading@11: 
yading@11:     atexit(avisynth_atexit_handler);
yading@11:     return 0;
yading@11: 
yading@11: fail:
yading@11:     FreeLibrary(avs_library->library);
yading@11: init_fail:
yading@11:     av_freep(&avs_library);
yading@11:     return AVERROR_UNKNOWN;
yading@11: }
yading@11: 
yading@11: // Note that avisynth_context_create and avisynth_context_destroy
yading@11: // do not allocate or free the actual context! That is taken care of
yading@11: // by libavformat.
yading@11: static av_cold int avisynth_context_create(AVFormatContext *s) {
yading@11:     AviSynthContext *avs = (AviSynthContext *)s->priv_data;
yading@11:     int ret;
yading@11: 
yading@11:     if (!avs_library) {
yading@11:         if (ret = avisynth_load_library())
yading@11:             return ret;
yading@11:     }
yading@11: 
yading@11:     avs->env = avs_library->avs_create_script_environment(3);
yading@11:     if (avs_library->avs_get_error) {
yading@11:         const char *error = avs_library->avs_get_error(avs->env);
yading@11:         if (error) {
yading@11:             av_log(s, AV_LOG_ERROR, "%s\n", error);
yading@11:             return AVERROR_UNKNOWN;
yading@11:         }
yading@11:     }
yading@11: 
yading@11:     if (!avs_ctx_list) {
yading@11:         avs_ctx_list = avs;
yading@11:     } else {
yading@11:         avs->next = avs_ctx_list;
yading@11:         avs_ctx_list = avs;
yading@11:     }
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static av_cold void avisynth_context_destroy(AviSynthContext *avs) {
yading@11:     if (avs_atexit_called)
yading@11:        return;
yading@11: 
yading@11:     if (avs == avs_ctx_list) {
yading@11:         avs_ctx_list = avs->next;
yading@11:     } else {
yading@11:         AviSynthContext *prev = avs_ctx_list;
yading@11:         while (prev->next != avs)
yading@11:             prev = prev->next;
yading@11:         prev->next = avs->next;
yading@11:     }
yading@11: 
yading@11:     if (avs->clip) {
yading@11:         avs_library->avs_release_clip(avs->clip);
yading@11:         avs->clip = NULL;
yading@11:     }
yading@11:     if (avs->env) {
yading@11:         avs_library->avs_delete_script_environment(avs->env);
yading@11:         avs->env = NULL;
yading@11:     }
yading@11: }
yading@11: 
yading@11: static av_cold void avisynth_atexit_handler(void) {
yading@11:     AviSynthContext *avs = avs_ctx_list;
yading@11: 
yading@11:     while (avs) {
yading@11:         AviSynthContext *next = avs->next;
yading@11:         avisynth_context_destroy(avs);
yading@11:         avs = next;
yading@11:     }
yading@11:     FreeLibrary(avs_library->library);
yading@11:     av_freep(&avs_library);
yading@11: 
yading@11:     avs_atexit_called = 1;
yading@11: }
yading@11: 
yading@11: // Create AVStream from audio and video data.
yading@11: static int avisynth_create_stream_video(AVFormatContext *s, AVStream *st) {
yading@11:     AviSynthContext *avs = s->priv_data;
yading@11:     int planar = 0; // 0: packed, 1: YUV, 2: Y8
yading@11: 
yading@11:     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
yading@11:     st->codec->codec_id = CODEC_ID_RAWVIDEO;
yading@11:     st->codec->width = avs->vi->width;
yading@11:     st->codec->height = avs->vi->height;
yading@11: 
yading@11:     st->time_base = (AVRational) {avs->vi->fps_denominator, avs->vi->fps_numerator};
yading@11:     st->avg_frame_rate = (AVRational) {avs->vi->fps_numerator, avs->vi->fps_denominator};
yading@11:     st->start_time = 0;
yading@11:     st->duration = avs->vi->num_frames;
yading@11:     st->nb_frames = avs->vi->num_frames;
yading@11: 
yading@11:     switch (avs->vi->pixel_type) {
yading@11: #ifdef _WIN32
yading@11:     case AVS_CS_YV24:
yading@11:         st->codec->pix_fmt = PIX_FMT_YUV444P;
yading@11:         planar = 1;
yading@11:         break;
yading@11:     case AVS_CS_YV16:
yading@11:         st->codec->pix_fmt = PIX_FMT_YUV422P;
yading@11:         planar = 1;
yading@11:         break;
yading@11:     case AVS_CS_YV411:
yading@11:         st->codec->pix_fmt = PIX_FMT_YUV411P;
yading@11:         planar = 1;
yading@11:         break;
yading@11:     case AVS_CS_Y8:
yading@11:         st->codec->pix_fmt = PIX_FMT_GRAY8;
yading@11:         planar = 2;
yading@11:         break;
yading@11: #endif
yading@11:     case AVS_CS_BGR24:
yading@11:         st->codec->pix_fmt = PIX_FMT_BGR24;
yading@11:         break;
yading@11:     case AVS_CS_BGR32:
yading@11:         st->codec->pix_fmt = PIX_FMT_RGB32;
yading@11:         break;
yading@11:     case AVS_CS_YUY2:
yading@11:         st->codec->pix_fmt = PIX_FMT_YUYV422;
yading@11:         break;
yading@11:     case AVS_CS_YV12:
yading@11:         st->codec->pix_fmt = PIX_FMT_YUV420P;
yading@11:         planar = 1;
yading@11:         break;
yading@11:     case AVS_CS_I420: // Is this even used anywhere?
yading@11:         st->codec->pix_fmt = PIX_FMT_YUV420P;
yading@11:         planar = 1;
yading@11:         break;
yading@11:     default:
yading@11:         av_log(s, AV_LOG_ERROR, "unknown AviSynth colorspace %d\n", avs->vi->pixel_type);
yading@11:         avs->error = 1;
yading@11:         return AVERROR_UNKNOWN;
yading@11:     }
yading@11: 
yading@11:     switch (planar) {
yading@11:     case 2: // Y8
yading@11:         avs->n_planes = 1;
yading@11:         avs->planes = avs_planes_grey;
yading@11:         break;
yading@11:     case 1: // YUV
yading@11:         avs->n_planes = 3;
yading@11:         avs->planes = avs_planes_yuv;
yading@11:         break;
yading@11:     default:
yading@11:         avs->n_planes = 1;
yading@11:         avs->planes = avs_planes_packed;
yading@11:     }
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int avisynth_create_stream_audio(AVFormatContext *s, AVStream *st) {
yading@11:     AviSynthContext *avs = s->priv_data;
yading@11: 
yading@11:     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
yading@11:     st->codec->sample_rate = avs->vi->audio_samples_per_second;
yading@11:     st->codec->channels = avs->vi->nchannels;
yading@11:     st->time_base = (AVRational) {1, avs->vi->audio_samples_per_second};
yading@11: 
yading@11:     switch (avs->vi->sample_type) {
yading@11:     case AVS_SAMPLE_INT8:
yading@11:         st->codec->codec_id = CODEC_ID_PCM_U8;
yading@11:         break;
yading@11:     case AVS_SAMPLE_INT16:
yading@11:         st->codec->codec_id = CODEC_ID_PCM_S16LE;
yading@11:         break;
yading@11:     case AVS_SAMPLE_INT24:
yading@11:         st->codec->codec_id = CODEC_ID_PCM_S24LE;
yading@11:         break;
yading@11:     case AVS_SAMPLE_INT32:
yading@11:         st->codec->codec_id = CODEC_ID_PCM_S32LE;
yading@11:         break;
yading@11:     case AVS_SAMPLE_FLOAT:
yading@11:         st->codec->codec_id = CODEC_ID_PCM_F32LE;
yading@11:         break;
yading@11:     default:
yading@11:         av_log(s, AV_LOG_ERROR, "unknown AviSynth sample type %d\n", avs->vi->sample_type);
yading@11:         avs->error = 1;
yading@11:         return AVERROR_UNKNOWN;
yading@11:     }
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int avisynth_create_stream(AVFormatContext *s) {
yading@11:     AviSynthContext *avs = s->priv_data;
yading@11:     AVStream *st;
yading@11:     int ret;
yading@11:     int id = 0;
yading@11: 
yading@11:     if (avs_has_video(avs->vi)) {
yading@11:         st = avformat_new_stream(s, NULL);
yading@11:         if (!st)
yading@11:             return AVERROR_UNKNOWN;
yading@11:         st->id = id++;
yading@11:         if (ret = avisynth_create_stream_video(s, st))
yading@11:             return ret;
yading@11:     }
yading@11:     if (avs_has_audio(avs->vi)) {
yading@11:         st = avformat_new_stream(s, NULL);
yading@11:         if (!st)
yading@11:             return AVERROR_UNKNOWN;
yading@11:         st->id = id++;
yading@11:         if (ret = avisynth_create_stream_audio(s, st))
yading@11:             return ret;
yading@11:     }
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int avisynth_open_file(AVFormatContext *s) {
yading@11:     AviSynthContext *avs = (AviSynthContext *)s->priv_data;
yading@11:     AVS_Value arg, val;
yading@11:     int ret;
yading@11: 
yading@11:     if (ret = avisynth_context_create(s))
yading@11:         return ret;
yading@11: 
yading@11:     arg = avs_new_value_string(s->filename);
yading@11:     val = avs_library->avs_invoke(avs->env, "Import", arg, 0);
yading@11:     if (avs_is_error(val)) {
yading@11:         av_log(s, AV_LOG_ERROR, "%s\n", avs_as_error(val));
yading@11:         ret = AVERROR_UNKNOWN;
yading@11:         goto fail;
yading@11:     }
yading@11:     if (!avs_is_clip(val)) {
yading@11:         av_log(s, AV_LOG_ERROR, "%s\n", "AviSynth script did not return a clip");
yading@11:         ret = AVERROR_UNKNOWN;
yading@11:         goto fail;
yading@11:     }
yading@11: 
yading@11:     avs->clip = avs_library->avs_take_clip(val, avs->env);
yading@11:     avs->vi = avs_library->avs_get_video_info(avs->clip);
yading@11: 
yading@11:     // Release the AVS_Value as it will go out of scope.
yading@11:     avs_library->avs_release_value(val);
yading@11: 
yading@11:     if (ret = avisynth_create_stream(s))
yading@11:         goto fail;
yading@11: 
yading@11:     return 0;
yading@11: 
yading@11: fail:
yading@11:     avisynth_context_destroy(avs);
yading@11:     return ret;
yading@11: }
yading@11: 
yading@11: static void avisynth_next_stream(AVFormatContext *s, AVStream **st, AVPacket *pkt, int *discard) {
yading@11:     AviSynthContext *avs = s->priv_data;
yading@11: 
yading@11:     pkt->stream_index = avs->curr_stream++;
yading@11:     avs->curr_stream %= s->nb_streams;
yading@11: 
yading@11:     *st = s->streams[pkt->stream_index];
yading@11:     if ((*st)->discard == AVDISCARD_ALL)
yading@11:         *discard = 1;
yading@11:     else
yading@11:         *discard = 0;
yading@11: 
yading@11:     return;
yading@11: }
yading@11: 
yading@11: // Copy AviSynth clip data into an AVPacket.
yading@11: static int avisynth_read_packet_video(AVFormatContext *s, AVPacket *pkt, int discard) {
yading@11:     AviSynthContext *avs = s->priv_data;
yading@11:     AVS_VideoFrame *frame;
yading@11:     unsigned char *dst_p;
yading@11:     const unsigned char *src_p;
yading@11:     int n, i, plane, rowsize, planeheight, pitch, bits;
yading@11:     const char *error;
yading@11: 
yading@11:     if (avs->curr_frame >= avs->vi->num_frames)
yading@11:         return AVERROR_EOF;
yading@11: 
yading@11:     // This must happen even if the stream is discarded to prevent desync.
yading@11:     n = avs->curr_frame++;
yading@11:     if (discard)
yading@11:         return 0;
yading@11: 
yading@11:     pkt->pts = n;
yading@11:     pkt->dts = n;
yading@11:     pkt->duration = 1;
yading@11: 
yading@11:     // Define the bpp values for the new AviSynth 2.6 colorspaces
yading@11:     if (avs_is_yv24(avs->vi)) {
yading@11:         bits = 24;
yading@11:     } else if (avs_is_yv16(avs->vi)) {
yading@11:         bits = 16;
yading@11:     } else if (avs_is_yv411(avs->vi)) {
yading@11:         bits = 12;
yading@11:     } else if (avs_is_y8(avs->vi)) {
yading@11:         bits = 8;
yading@11:     } else {
yading@11:         bits = avs_bits_per_pixel(avs->vi);
yading@11:     }
yading@11: 
yading@11:     // Without cast to int64_t, calculation overflows at about 9k x 9k resolution.
yading@11:     pkt->size = (((int64_t)avs->vi->width * (int64_t)avs->vi->height) * bits) / 8;
yading@11:     if (!pkt->size)
yading@11:         return AVERROR_UNKNOWN;
yading@11:     pkt->data = av_malloc(pkt->size);
yading@11:     if (!pkt->data)
yading@11:         return AVERROR_UNKNOWN;
yading@11: 
yading@11:     frame = avs_library->avs_get_frame(avs->clip, n);
yading@11:     error = avs_library->avs_clip_get_error(avs->clip);
yading@11:     if (error) {
yading@11:         av_log(s, AV_LOG_ERROR, "%s\n", error);
yading@11:         avs->error = 1;
yading@11:         av_freep(&pkt->data);
yading@11:         return AVERROR_UNKNOWN;
yading@11:     }
yading@11: 
yading@11:     dst_p = pkt->data;
yading@11:     for (i = 0; i < avs->n_planes; i++) {
yading@11:         plane = avs->planes[i];
yading@11:         src_p = avs_get_read_ptr_p(frame, plane);
yading@11:         rowsize = avs_get_row_size_p(frame, plane);
yading@11:         planeheight = avs_get_height_p(frame, plane);
yading@11:         pitch = avs_get_pitch_p(frame, plane);
yading@11: 
yading@11:         // Flip RGB video.
yading@11:         if (avs_is_rgb24(avs->vi) || avs_is_rgb(avs->vi)) {
yading@11:             src_p = src_p + (planeheight - 1) * pitch;
yading@11:             pitch = -pitch;
yading@11:         }
yading@11: 
yading@11:         avs_library->avs_bit_blt(avs->env, dst_p, rowsize, src_p, pitch, rowsize, planeheight);
yading@11:         dst_p += rowsize * planeheight;
yading@11:     }
yading@11: 
yading@11:     avs_library->avs_release_video_frame(frame);
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int avisynth_read_packet_audio(AVFormatContext *s, AVPacket *pkt, int discard) {
yading@11:     AviSynthContext *avs = s->priv_data;
yading@11:     AVRational fps, samplerate;
yading@11:     int samples;
yading@11:     int64_t n;
yading@11:     const char *error;
yading@11: 
yading@11:     if (avs->curr_sample >= avs->vi->num_audio_samples)
yading@11:         return AVERROR_EOF;
yading@11: 
yading@11:     fps.num = avs->vi->fps_numerator;
yading@11:     fps.den = avs->vi->fps_denominator;
yading@11:     samplerate.num = avs->vi->audio_samples_per_second;
yading@11:     samplerate.den = 1;
yading@11: 
yading@11:     if (avs_has_video(avs->vi)) {
yading@11:         if (avs->curr_frame < avs->vi->num_frames)
yading@11:             samples = av_rescale_q(avs->curr_frame, samplerate, fps) - avs->curr_sample;
yading@11:         else
yading@11:             samples = av_rescale_q(1, samplerate, fps);
yading@11:     } else {
yading@11:         samples = 1000;
yading@11:     }
yading@11: 
yading@11:     // After seeking, audio may catch up with video.
yading@11:     if (samples <= 0) {
yading@11:         pkt->size = 0;
yading@11:         pkt->data = NULL;
yading@11:         return 0;
yading@11:     }
yading@11: 
yading@11:     if (avs->curr_sample + samples > avs->vi->num_audio_samples)
yading@11:         samples = avs->vi->num_audio_samples - avs->curr_sample;
yading@11: 
yading@11:     // This must happen even if the stream is discarded to prevent desync.
yading@11:     n = avs->curr_sample;
yading@11:     avs->curr_sample += samples;
yading@11:     if (discard)
yading@11:         return 0;
yading@11: 
yading@11:     pkt->pts = n;
yading@11:     pkt->dts = n;
yading@11:     pkt->duration = samples;
yading@11: 
yading@11:     pkt->size = avs_bytes_per_channel_sample(avs->vi) * samples * avs->vi->nchannels;
yading@11:     if (!pkt->size)
yading@11:         return AVERROR_UNKNOWN;
yading@11:     pkt->data = av_malloc(pkt->size);
yading@11:     if (!pkt->data)
yading@11:         return AVERROR_UNKNOWN;
yading@11: 
yading@11:     avs_library->avs_get_audio(avs->clip, pkt->data, n, samples);
yading@11:     error = avs_library->avs_clip_get_error(avs->clip);
yading@11:     if (error) {
yading@11:         av_log(s, AV_LOG_ERROR, "%s\n", error);
yading@11:         avs->error = 1;
yading@11:         av_freep(&pkt->data);
yading@11:         return AVERROR_UNKNOWN;
yading@11:     }
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static av_cold int avisynth_read_header(AVFormatContext *s) {
yading@11:     int ret;
yading@11: 
yading@11:     // Calling library must implement a lock for thread-safe opens.
yading@11:     if (ret = avpriv_lock_avformat())
yading@11:         return ret;
yading@11: 
yading@11:     if (ret = avisynth_open_file(s)) {
yading@11:         avpriv_unlock_avformat();
yading@11:         return ret;
yading@11:     }
yading@11: 
yading@11:     avpriv_unlock_avformat();
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int avisynth_read_packet(AVFormatContext *s, AVPacket *pkt) {
yading@11:     AviSynthContext *avs = s->priv_data;
yading@11:     AVStream *st;
yading@11:     int discard = 0;
yading@11:     int ret;
yading@11: 
yading@11:     if (avs->error)
yading@11:         return AVERROR_UNKNOWN;
yading@11: 
yading@11:     pkt->destruct = av_destruct_packet;
yading@11: 
yading@11:     // If either stream reaches EOF, try to read the other one before giving up.
yading@11:     avisynth_next_stream(s, &st, pkt, &discard);
yading@11:     if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
yading@11:         ret = avisynth_read_packet_video(s, pkt, discard);
yading@11:         if (ret == AVERROR_EOF && avs_has_audio(avs->vi)) {
yading@11:             avisynth_next_stream(s, &st, pkt, &discard);
yading@11:             return avisynth_read_packet_audio(s, pkt, discard);
yading@11:         }
yading@11:         return ret;
yading@11:     } else {
yading@11:         ret = avisynth_read_packet_audio(s, pkt, discard);
yading@11:         if (ret == AVERROR_EOF && avs_has_video(avs->vi)) {
yading@11:             avisynth_next_stream(s, &st, pkt, &discard);
yading@11:             return avisynth_read_packet_video(s, pkt, discard);
yading@11:         }
yading@11:         return ret;
yading@11:     }
yading@11: }
yading@11: 
yading@11: static av_cold int avisynth_read_close(AVFormatContext *s) {
yading@11:     if (avpriv_lock_avformat())
yading@11:         return AVERROR_UNKNOWN;
yading@11: 
yading@11:     avisynth_context_destroy(s->priv_data);
yading@11:     avpriv_unlock_avformat();
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int avisynth_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) {
yading@11:     AviSynthContext *avs = s->priv_data;
yading@11:     AVStream *st;
yading@11:     AVRational fps, samplerate;
yading@11: 
yading@11:     if (avs->error)
yading@11:         return AVERROR_UNKNOWN;
yading@11: 
yading@11:     fps = (AVRational) {avs->vi->fps_numerator, avs->vi->fps_denominator};
yading@11:     samplerate = (AVRational) {avs->vi->audio_samples_per_second, 1};
yading@11: 
yading@11:     st = s->streams[stream_index];
yading@11:     if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
yading@11:         // AviSynth frame counts are signed int.
yading@11:         if ((timestamp >= avs->vi->num_frames) || (timestamp > INT_MAX) || (timestamp < 0))
yading@11:             return AVERROR_EOF;
yading@11:         avs->curr_frame = timestamp;
yading@11:         if (avs_has_audio(avs->vi))
yading@11:             avs->curr_sample = av_rescale_q(timestamp, samplerate, fps);
yading@11:     } else {
yading@11:         if ((timestamp >= avs->vi->num_audio_samples) || (timestamp < 0))
yading@11:             return AVERROR_EOF;
yading@11:         // Force frame granularity for seeking.
yading@11:         if (avs_has_video(avs->vi)) {
yading@11:             avs->curr_frame = av_rescale_q(timestamp, fps, samplerate);
yading@11:             avs->curr_sample = av_rescale_q(avs->curr_frame, samplerate, fps);
yading@11:         } else {
yading@11:             avs->curr_sample = timestamp;
yading@11:         }
yading@11:     }
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: AVInputFormat ff_avisynth_demuxer = {
yading@11:     .name           = "avisynth",
yading@11:     .long_name      = NULL_IF_CONFIG_SMALL("AviSynth script"),
yading@11:     .priv_data_size = sizeof(AviSynthContext),
yading@11:     .read_header    = avisynth_read_header,
yading@11:     .read_packet    = avisynth_read_packet,
yading@11:     .read_close     = avisynth_read_close,
yading@11:     .read_seek      = avisynth_read_seek,
yading@11:     .extensions     = "avs",
yading@11: };