/*

  * filter layer

  * Copyright (c) 2007 Bobby Bingham

  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * 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
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 

 #include "libavutil/avassert.h"
 #include "libavutil/avstring.h"

 #include "libavutil/channel_layout.h"

 #include "libavutil/common.h"

 #include "libavutil/imgutils.h"

 #include "libavutil/pixdesc.h"

 #include "libavutil/rational.h"

 #include "libavutil/samplefmt.h"

 #include "audio.h"

 #include "avfilter.h"

 #include "formats.h"

 #include "internal.h"

 #include "audio.h"

 static int ff_filter_frame_framed(AVFilterLink *link, AVFilterBufferRef *frame);
 

 char *ff_get_ref_perms_string(char *buf, size_t buf_size, int perms)
 {
     snprintf(buf, buf_size, "%s%s%s%s%s%s",
              perms & AV_PERM_READ      ? "r" : "",
              perms & AV_PERM_WRITE     ? "w" : "",
              perms & AV_PERM_PRESERVE  ? "p" : "",
              perms & AV_PERM_REUSE     ? "u" : "",
              perms & AV_PERM_REUSE2    ? "U" : "",
              perms & AV_PERM_NEG_LINESIZES ? "n" : "");
     return buf;
 }
 

 void ff_tlog_ref(void *ctx, AVFilterBufferRef *ref, int end)

 {
     av_unused char buf[16];

     ff_tlog(ctx,

             "ref[%p buf:%p refcount:%d perms:%s data:%p linesize[%d, %d, %d, %d] pts:%"PRId64" pos:%"PRId64,
             ref, ref->buf, ref->buf->refcount, ff_get_ref_perms_string(buf, sizeof(buf), ref->perms), ref->data[0],
             ref->linesize[0], ref->linesize[1], ref->linesize[2], ref->linesize[3],
             ref->pts, ref->pos);
 
     if (ref->video) {

         ff_tlog(ctx, " a:%d/%d s:%dx%d i:%c iskey:%d type:%c",

                 ref->video->sample_aspect_ratio.num, ref->video->sample_aspect_ratio.den,
                 ref->video->w, ref->video->h,
                 !ref->video->interlaced     ? 'P' :         /* Progressive  */
                 ref->video->top_field_first ? 'T' : 'B',    /* Top / Bottom */
                 ref->video->key_frame,
                 av_get_picture_type_char(ref->video->pict_type));
     }
     if (ref->audio) {

         ff_tlog(ctx, " cl:%"PRId64"d n:%d r:%d",

                 ref->audio->channel_layout,
                 ref->audio->nb_samples,
                 ref->audio->sample_rate);
     }
 

     ff_tlog(ctx, "]%s", end ? "\n" : "");

 }
 

 unsigned avfilter_version(void) {

     av_assert0(LIBAVFILTER_VERSION_MICRO >= 100);

     return LIBAVFILTER_VERSION_INT;
 }
 

 const char *avfilter_configuration(void)

 {

     return FFMPEG_CONFIGURATION;

 }
 

 const char *avfilter_license(void)

 {
 #define LICENSE_PREFIX "libavfilter license: "

     return LICENSE_PREFIX FFMPEG_LICENSE + sizeof(LICENSE_PREFIX) - 1;

 }
 

 void ff_command_queue_pop(AVFilterContext *filter)

 {
     AVFilterCommand *c= filter->command_queue;
     av_freep(&c->arg);
     av_freep(&c->command);
     filter->command_queue= c->next;
     av_free(c);
 }
 

 void ff_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
                    AVFilterPad **pads, AVFilterLink ***links,
                    AVFilterPad *newpad)

 {
     unsigned i;
 
     idx = FFMIN(idx, *count);
 
     *pads  = av_realloc(*pads,  sizeof(AVFilterPad)   * (*count + 1));
     *links = av_realloc(*links, sizeof(AVFilterLink*) * (*count + 1));
     memmove(*pads +idx+1, *pads +idx, sizeof(AVFilterPad)   * (*count-idx));
     memmove(*links+idx+1, *links+idx, sizeof(AVFilterLink*) * (*count-idx));
     memcpy(*pads+idx, newpad, sizeof(AVFilterPad));
     (*links)[idx] = NULL;
 

     (*count)++;

     for (i = idx + 1; i < *count; i++)
         if ((*links)[i])
             (*(unsigned *)((uint8_t *) (*links)[i] + padidx_off))++;

 }
 

 int avfilter_link(AVFilterContext *src, unsigned srcpad,
                   AVFilterContext *dst, unsigned dstpad)
 {
     AVFilterLink *link;
 

     if (src->nb_outputs <= srcpad || dst->nb_inputs <= dstpad ||
         src->outputs[srcpad]      || dst->inputs[dstpad])

         return -1;
 

     if (src->output_pads[srcpad].type != dst->input_pads[dstpad].type) {
         av_log(src, AV_LOG_ERROR,

                "Media type mismatch between the '%s' filter output pad %d (%s) and the '%s' filter input pad %d (%s)\n",
                src->name, srcpad, (char *)av_x_if_null(av_get_media_type_string(src->output_pads[srcpad].type), "?"),
                dst->name, dstpad, (char *)av_x_if_null(av_get_media_type_string(dst-> input_pads[dstpad].type), "?"));

         return AVERROR(EINVAL);
     }
 

     src->outputs[srcpad] =

     dst-> inputs[dstpad] = link = av_mallocz(sizeof(AVFilterLink));

     link->src     = src;
     link->dst     = dst;

     link->srcpad  = &src->output_pads[srcpad];
     link->dstpad  = &dst->input_pads[dstpad];

     link->type    = src->output_pads[srcpad].type;

     av_assert0(AV_PIX_FMT_NONE == -1 && AV_SAMPLE_FMT_NONE == -1);

     link->format  = -1;

 
     return 0;
 }
 

 void avfilter_link_free(AVFilterLink **link)
 {
     if (!*link)
         return;
 

     if ((*link)->pool)

         ff_free_pool((*link)->pool);

     avfilter_unref_bufferp(&(*link)->partial_buf);
 

     av_freep(link);
 }
 

 int avfilter_link_get_channels(AVFilterLink *link)
 {
     return link->channels;
 }
 

 void avfilter_link_set_closed(AVFilterLink *link, int closed)
 {
     link->closed = closed;
 }
 

 int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,

                            unsigned filt_srcpad_idx, unsigned filt_dstpad_idx)

 {

     int ret;

     unsigned dstpad_idx = link->dstpad - link->dst->input_pads;
 

     av_log(link->dst, AV_LOG_VERBOSE, "auto-inserting filter '%s' "

            "between the filter '%s' and the filter '%s'\n",
            filt->name, link->src->name, link->dst->name);

     link->dst->inputs[dstpad_idx] = NULL;

     if ((ret = avfilter_link(filt, filt_dstpad_idx, link->dst, dstpad_idx)) < 0) {

         /* failed to link output filter to new filter */

         link->dst->inputs[dstpad_idx] = link;

         return ret;

     }
 
     /* re-hookup the link to the new destination filter we inserted */
     link->dst = filt;

     link->dstpad = &filt->input_pads[filt_srcpad_idx];
     filt->inputs[filt_srcpad_idx] = link;

     /* if any information on supported media formats already exists on the

      * link, we need to preserve that */

     if (link->out_formats)

         ff_formats_changeref(&link->out_formats,

                                    &filt->outputs[filt_dstpad_idx]->out_formats);

     if (link->out_samplerates)

         ff_formats_changeref(&link->out_samplerates,

                                    &filt->outputs[filt_dstpad_idx]->out_samplerates);
     if (link->out_channel_layouts)
         ff_channel_layouts_changeref(&link->out_channel_layouts,
                                      &filt->outputs[filt_dstpad_idx]->out_channel_layouts);

     return 0;
 }
 

 int avfilter_config_links(AVFilterContext *filter)

 {
     int (*config_link)(AVFilterLink *);

     unsigned i;

     int ret;

     for (i = 0; i < filter->nb_inputs; i ++) {

         AVFilterLink *link = filter->inputs[i];

         AVFilterLink *inlink = link->src->nb_inputs ?

             link->src->inputs[0] : NULL;

         if (!link) continue;

         link->current_pts = AV_NOPTS_VALUE;
 

         switch (link->init_state) {

         case AVLINK_INIT:
             continue;
         case AVLINK_STARTINIT:

             av_log(filter, AV_LOG_INFO, "circular filter chain detected\n");
             return 0;

         case AVLINK_UNINIT:
             link->init_state = AVLINK_STARTINIT;
 

             if ((ret = avfilter_config_links(link->src)) < 0)
                 return ret;

             if (!(config_link = link->srcpad->config_props)) {

                 if (link->src->nb_inputs != 1) {

                     av_log(link->src, AV_LOG_ERROR, "Source filters and filters "
                                                     "with more than one input "
                                                     "must set config_props() "
                                                     "callbacks on all outputs\n");
                     return AVERROR(EINVAL);
                 }

             } else if ((ret = config_link(link)) < 0) {
                 av_log(link->src, AV_LOG_ERROR,
                        "Failed to configure output pad on %s\n",
                        link->src->name);

                 return ret;

             }

             switch (link->type) {
             case AVMEDIA_TYPE_VIDEO:
                 if (!link->time_base.num && !link->time_base.den)

                     link->time_base = inlink ? inlink->time_base : AV_TIME_BASE_Q;

 
                 if (!link->sample_aspect_ratio.num && !link->sample_aspect_ratio.den)

                     link->sample_aspect_ratio = inlink ?
                         inlink->sample_aspect_ratio : (AVRational){1,1};

                 if (inlink && !link->frame_rate.num && !link->frame_rate.den)
                     link->frame_rate = inlink->frame_rate;
 

                 if (inlink) {

                     if (!link->w)

                         link->w = inlink->w;

                     if (!link->h)

                         link->h = inlink->h;

                 } else if (!link->w || !link->h) {
                     av_log(link->src, AV_LOG_ERROR,
                            "Video source filters must set their output link's "
                            "width and height\n");
                     return AVERROR(EINVAL);
                 }
                 break;
 
             case AVMEDIA_TYPE_AUDIO:

                 if (inlink) {

                     if (!link->time_base.num && !link->time_base.den)

                         link->time_base = inlink->time_base;

                 }

 
                 if (!link->time_base.num && !link->time_base.den)
                     link->time_base = (AVRational) {1, link->sample_rate};

             }

             if ((config_link = link->dstpad->config_props))

                 if ((ret = config_link(link)) < 0) {
                     av_log(link->src, AV_LOG_ERROR,
                            "Failed to configure input pad on %s\n",
                            link->dst->name);

                     return ret;

                 }

             link->init_state = AVLINK_INIT;
         }
     }
 

     return 0;
 }
 

 void ff_tlog_link(void *ctx, AVFilterLink *link, int end)

 {

     if (link->type == AVMEDIA_TYPE_VIDEO) {

         ff_tlog(ctx,

                 "link[%p s:%dx%d fmt:%s %s->%s]%s",

                 link, link->w, link->h,

                 av_get_pix_fmt_name(link->format),

                 link->src ? link->src->filter->name : "",
                 link->dst ? link->dst->filter->name : "",
                 end ? "\n" : "");

     } else {
         char buf[128];
         av_get_channel_layout_string(buf, sizeof(buf), -1, link->channel_layout);
 

         ff_tlog(ctx,

                 "link[%p r:%d cl:%s fmt:%s %s->%s]%s",

                 link, (int)link->sample_rate, buf,

                 av_get_sample_fmt_name(link->format),
                 link->src ? link->src->filter->name : "",
                 link->dst ? link->dst->filter->name : "",
                 end ? "\n" : "");
     }

 }
 

 int ff_request_frame(AVFilterLink *link)

 {

     int ret = -1;

     FF_TPRINTF_START(NULL, request_frame); ff_tlog_link(NULL, link, 1);

     if (link->closed)
         return AVERROR_EOF;

     if (link->srcpad->request_frame)

         ret = link->srcpad->request_frame(link);

     else if (link->src->inputs[0])

         ret = ff_request_frame(link->src->inputs[0]);
     if (ret == AVERROR_EOF && link->partial_buf) {
         AVFilterBufferRef *pbuf = link->partial_buf;
         link->partial_buf = NULL;

         ff_filter_frame_framed(link, pbuf);

         return 0;
     }

     if (ret == AVERROR_EOF)
         link->closed = 1;

     return ret;

 }
 

 int ff_poll_frame(AVFilterLink *link)

 {

     int i, min = INT_MAX;

     if (link->srcpad->poll_frame)
         return link->srcpad->poll_frame(link);

     for (i = 0; i < link->src->nb_inputs; i++) {

         int val;

         if (!link->src->inputs[i])

             return -1;

         val = ff_poll_frame(link->src->inputs[i]);

         min = FFMIN(min, val);

     }

 
     return min;
 }
 

 void ff_update_link_current_pts(AVFilterLink *link, int64_t pts)

 {

     if (pts == AV_NOPTS_VALUE)

         return;

     link->current_pts = av_rescale_q(pts, link->time_base, AV_TIME_BASE_Q);
     /* TODO use duration */

     if (link->graph && link->age_index >= 0)
         ff_avfilter_graph_update_heap(link->graph, link);
 }
 

 int avfilter_process_command(AVFilterContext *filter, const char *cmd, const char *arg, char *res, int res_len, int flags)
 {
     if(!strcmp(cmd, "ping")){
         av_strlcatf(res, res_len, "pong from:%s %s\n", filter->filter->name, filter->name);
         return 0;
     }else if(filter->filter->process_command) {
         return filter->filter->process_command(filter, cmd, arg, res, res_len, flags);
     }
     return AVERROR(ENOSYS);
 }
 

 #define MAX_REGISTERED_AVFILTERS_NB 128

 
 static AVFilter *registered_avfilters[MAX_REGISTERED_AVFILTERS_NB + 1];
 
 static int next_registered_avfilter_idx = 0;

 AVFilter *avfilter_get_by_name(const char *name)

 {

     int i;

     for (i = 0; registered_avfilters[i]; i++)
         if (!strcmp(registered_avfilters[i]->name, name))
             return registered_avfilters[i];

 
     return NULL;
 }
 

 int avfilter_register(AVFilter *filter)

 {

     int i;
 

     if (next_registered_avfilter_idx == MAX_REGISTERED_AVFILTERS_NB) {
         av_log(NULL, AV_LOG_ERROR,
                "Maximum number of registered filters %d reached, "
                "impossible to register filter with name '%s'\n",
                MAX_REGISTERED_AVFILTERS_NB, filter->name);
         return AVERROR(ENOMEM);
     }

     for(i=0; filter->inputs && filter->inputs[i].name; i++) {
         const AVFilterPad *input = &filter->inputs[i];
         av_assert0(     !input->filter_frame

                     || (!input->start_frame && !input->end_frame));

     }
 

     registered_avfilters[next_registered_avfilter_idx++] = filter;
     return 0;

 }
 

 AVFilter **av_filter_next(AVFilter **filter)
 {
     return filter ? ++filter : &registered_avfilters[0];
 }
 

 void avfilter_uninit(void)
 {

     memset(registered_avfilters, 0, sizeof(registered_avfilters));
     next_registered_avfilter_idx = 0;

 }
 
 static int pad_count(const AVFilterPad *pads)
 {
     int count;
 

     if (!pads)
         return 0;
 

     for(count = 0; pads->name; count ++) pads ++;

     return count;
 }
 

 static const char *default_filter_name(void *filter_ctx)

 {

     AVFilterContext *ctx = filter_ctx;
     return ctx->name ? ctx->name : ctx->filter->name;

 }
 

 static void *filter_child_next(void *obj, void *prev)
 {
     AVFilterContext *ctx = obj;
     if (!prev && ctx->filter && ctx->filter->priv_class)
         return ctx->priv;
     return NULL;
 }
 
 static const AVClass *filter_child_class_next(const AVClass *prev)
 {
     AVFilter **filter_ptr = NULL;
 
     /* find the filter that corresponds to prev */
     while (prev && *(filter_ptr = av_filter_next(filter_ptr)))
         if ((*filter_ptr)->priv_class == prev)
             break;
 
     /* could not find filter corresponding to prev */
     if (prev && !(*filter_ptr))
         return NULL;
 
     /* find next filter with specific options */
     while (*(filter_ptr = av_filter_next(filter_ptr)))
         if ((*filter_ptr)->priv_class)
             return (*filter_ptr)->priv_class;
     return NULL;
 }
 

 static const AVClass avfilter_class = {

     .class_name = "AVFilter",

     .item_name  = default_filter_name,

     .version    = LIBAVUTIL_VERSION_INT,

     .category   = AV_CLASS_CATEGORY_FILTER,

     .child_next = filter_child_next,
     .child_class_next = filter_child_class_next,

 };
 

 const AVClass *avfilter_get_class(void)
 {
     return &avfilter_class;
 }
 

 int avfilter_open(AVFilterContext **filter_ctx, AVFilter *filter, const char *inst_name)

 {

     AVFilterContext *ret;

     *filter_ctx = NULL;

 
     if (!filter)

         return AVERROR(EINVAL);

     ret = av_mallocz(sizeof(AVFilterContext));

     if (!ret)
         return AVERROR(ENOMEM);

     ret->av_class = &avfilter_class;

     ret->filter   = filter;

     ret->name     = inst_name ? av_strdup(inst_name) : NULL;

     if (filter->priv_size) {

         ret->priv     = av_mallocz(filter->priv_size);

         if (!ret->priv)
             goto err;
     }

     ret->nb_inputs = pad_count(filter->inputs);
     if (ret->nb_inputs ) {
         ret->input_pads   = av_malloc(sizeof(AVFilterPad) * ret->nb_inputs);

         if (!ret->input_pads)
             goto err;

         memcpy(ret->input_pads, filter->inputs, sizeof(AVFilterPad) * ret->nb_inputs);
         ret->inputs       = av_mallocz(sizeof(AVFilterLink*) * ret->nb_inputs);

         if (!ret->inputs)
             goto err;

     }

     ret->nb_outputs = pad_count(filter->outputs);
     if (ret->nb_outputs) {
         ret->output_pads  = av_malloc(sizeof(AVFilterPad) * ret->nb_outputs);

         if (!ret->output_pads)
             goto err;

         memcpy(ret->output_pads, filter->outputs, sizeof(AVFilterPad) * ret->nb_outputs);
         ret->outputs      = av_mallocz(sizeof(AVFilterLink*) * ret->nb_outputs);

         if (!ret->outputs)
             goto err;

     }

 #if FF_API_FOO_COUNT
     ret->output_count = ret->nb_outputs;
     ret->input_count  = ret->nb_inputs;
 #endif

     *filter_ctx = ret;
     return 0;

 
 err:
     av_freep(&ret->inputs);
     av_freep(&ret->input_pads);

     ret->nb_inputs = 0;

     av_freep(&ret->outputs);
     av_freep(&ret->output_pads);

     ret->nb_outputs = 0;

     av_freep(&ret->priv);
     av_free(ret);
     return AVERROR(ENOMEM);

 }
 

 void avfilter_free(AVFilterContext *filter)

 {
     int i;

     AVFilterLink *link;

     if (!filter)
         return;
 

     if (filter->filter->uninit)

         filter->filter->uninit(filter);
 

     for (i = 0; i < filter->nb_inputs; i++) {

         if ((link = filter->inputs[i])) {
             if (link->src)

                 link->src->outputs[link->srcpad - link->src->output_pads] = NULL;

             ff_formats_unref(&link->in_formats);
             ff_formats_unref(&link->out_formats);
             ff_formats_unref(&link->in_samplerates);
             ff_formats_unref(&link->out_samplerates);

             ff_channel_layouts_unref(&link->in_channel_layouts);
             ff_channel_layouts_unref(&link->out_channel_layouts);

         }

         avfilter_link_free(&link);

     }

     for (i = 0; i < filter->nb_outputs; i++) {

         if ((link = filter->outputs[i])) {
             if (link->dst)

                 link->dst->inputs[link->dstpad - link->dst->input_pads] = NULL;

             ff_formats_unref(&link->in_formats);
             ff_formats_unref(&link->out_formats);
             ff_formats_unref(&link->in_samplerates);
             ff_formats_unref(&link->out_samplerates);

             ff_channel_layouts_unref(&link->in_channel_layouts);
             ff_channel_layouts_unref(&link->out_channel_layouts);

         }

         avfilter_link_free(&link);

     }
 

     av_freep(&filter->name);
     av_freep(&filter->input_pads);
     av_freep(&filter->output_pads);
     av_freep(&filter->inputs);
     av_freep(&filter->outputs);
     av_freep(&filter->priv);

     while(filter->command_queue){

         ff_command_queue_pop(filter);

     }

     av_free(filter);
 }
 

 int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque)

 {

     int ret=0;

     if (filter->filter->init_opaque)
         ret = filter->filter->init_opaque(filter, args, opaque);
     else if (filter->filter->init)

         ret = filter->filter->init(filter, args);

     return ret;

 }

 const char *avfilter_pad_get_name(AVFilterPad *pads, int pad_idx)
 {
     return pads[pad_idx].name;
 }
 
 enum AVMediaType avfilter_pad_get_type(AVFilterPad *pads, int pad_idx)
 {
     return pads[pad_idx].type;

 }

 static int default_filter_frame(AVFilterLink *link, AVFilterBufferRef *frame)
 {
     return ff_filter_frame(link->dst->outputs[0], frame);
 }
 
 static int ff_filter_frame_framed(AVFilterLink *link, AVFilterBufferRef *frame)
 {
     int (*filter_frame)(AVFilterLink *, AVFilterBufferRef *);
     AVFilterPad *src = link->srcpad;
     AVFilterPad *dst = link->dstpad;
     AVFilterBufferRef *out;
     int perms, ret;
     AVFilterCommand *cmd= link->dst->command_queue;
     int64_t pts;
 
     if (link->closed) {
         avfilter_unref_buffer(frame);
         return AVERROR_EOF;
     }
 
     if (!(filter_frame = dst->filter_frame))
         filter_frame = default_filter_frame;
 
     av_assert1((frame->perms & src->min_perms) == src->min_perms);
     frame->perms &= ~ src->rej_perms;
     perms = frame->perms;
 
     if (frame->linesize[0] < 0)
         perms |= AV_PERM_NEG_LINESIZES;
 
     /* prepare to copy the frame if the buffer has insufficient permissions */
     if ((dst->min_perms & perms) != dst->min_perms ||
         dst->rej_perms & perms) {
         av_log(link->dst, AV_LOG_DEBUG,
                "Copying data in avfilter (have perms %x, need %x, reject %x)\n",
                perms, link->dstpad->min_perms, link->dstpad->rej_perms);
 
         /* Maybe use ff_copy_buffer_ref instead? */
         switch (link->type) {
         case AVMEDIA_TYPE_VIDEO:
             out = ff_get_video_buffer(link, dst->min_perms,
                                       link->w, link->h);
             break;
         case AVMEDIA_TYPE_AUDIO:
             out = ff_get_audio_buffer(link, dst->min_perms,
                                       frame->audio->nb_samples);
             break;
         default: return AVERROR(EINVAL);
         }
         if (!out) {
             avfilter_unref_buffer(frame);
             return AVERROR(ENOMEM);
         }
         avfilter_copy_buffer_ref_props(out, frame);
 
         switch (link->type) {
         case AVMEDIA_TYPE_VIDEO:
             av_image_copy(out->data, out->linesize, frame->data, frame->linesize,
                           frame->format, frame->video->w, frame->video->h);
             break;
         case AVMEDIA_TYPE_AUDIO:
             av_samples_copy(out->extended_data, frame->extended_data,
                             0, 0, frame->audio->nb_samples,
                             av_get_channel_layout_nb_channels(frame->audio->channel_layout),
                             frame->format);
             break;
         default: return AVERROR(EINVAL);
         }
 
         avfilter_unref_buffer(frame);
     } else
         out = frame;
 
     while(cmd && cmd->time <= frame->pts * av_q2d(link->time_base)){
         av_log(link->dst, AV_LOG_DEBUG,
                "Processing command time:%f command:%s arg:%s\n",
                cmd->time, cmd->command, cmd->arg);
         avfilter_process_command(link->dst, cmd->command, cmd->arg, 0, 0, cmd->flags);
         ff_command_queue_pop(link->dst);
         cmd= link->dst->command_queue;
     }
 
     pts = out->pts;
     ret = filter_frame(link, out);
     ff_update_link_current_pts(link, pts);
     return ret;
 }
 
 static int ff_filter_frame_needs_framing(AVFilterLink *link, AVFilterBufferRef *frame)
 {
     int insamples = frame->audio->nb_samples, inpos = 0, nb_samples;
     AVFilterBufferRef *pbuf = link->partial_buf;
     int nb_channels = frame->audio->channels;
     int ret = 0;
 
     /* Handle framing (min_samples, max_samples) */
     while (insamples) {
         if (!pbuf) {
             AVRational samples_tb = { 1, link->sample_rate };
             int perms = link->dstpad->min_perms | AV_PERM_WRITE;
             pbuf = ff_get_audio_buffer(link, perms, link->partial_buf_size);
             if (!pbuf) {
                 av_log(link->dst, AV_LOG_WARNING,
                        "Samples dropped due to memory allocation failure.\n");
                 return 0;
             }
             avfilter_copy_buffer_ref_props(pbuf, frame);
             pbuf->pts = frame->pts +
                         av_rescale_q(inpos, samples_tb, link->time_base);
             pbuf->audio->nb_samples = 0;
         }
         nb_samples = FFMIN(insamples,
                            link->partial_buf_size - pbuf->audio->nb_samples);
         av_samples_copy(pbuf->extended_data, frame->extended_data,
                         pbuf->audio->nb_samples, inpos,
                         nb_samples, nb_channels, link->format);
         inpos                   += nb_samples;
         insamples               -= nb_samples;
         pbuf->audio->nb_samples += nb_samples;
         if (pbuf->audio->nb_samples >= link->min_samples) {
             ret = ff_filter_frame_framed(link, pbuf);
             pbuf = NULL;
         }
     }
     avfilter_unref_buffer(frame);
     link->partial_buf = pbuf;
     return ret;
 }
 

 int ff_filter_frame(AVFilterLink *link, AVFilterBufferRef *frame)
 {
     FF_TPRINTF_START(NULL, filter_frame); ff_tlog_link(NULL, link, 1); ff_tlog(NULL, " "); ff_tlog_ref(NULL, frame, 1);
 

     /* Consistency checks */
     if (link->type == AVMEDIA_TYPE_VIDEO) {
         if (strcmp(link->dst->filter->name, "scale")) {
             av_assert1(frame->format                 == link->format);
             av_assert1(frame->video->w               == link->w);
             av_assert1(frame->video->h               == link->h);
         }
     } else {
         av_assert1(frame->format                == link->format);
         av_assert1(frame->audio->channels       == link->channels);
         av_assert1(frame->audio->channel_layout == link->channel_layout);
         av_assert1(frame->audio->sample_rate    == link->sample_rate);
     }
 
     /* Go directly to actual filtering if possible */
     if (link->type == AVMEDIA_TYPE_AUDIO &&
         link->min_samples &&
         (link->partial_buf ||
          frame->audio->nb_samples < link->min_samples ||
          frame->audio->nb_samples > link->max_samples)) {
         return ff_filter_frame_needs_framing(link, frame);
     } else {
         return ff_filter_frame_framed(link, frame);

     }
 }