libavfilter/buffersink.c

   1 /*
   2  * Copyright (c) 2011 Stefano Sabatini
   3  *
   4  * This file is part of Libav.
   5  *
   6  * Libav is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * Libav is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with Libav; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 /**
  22  * @file
  23  * buffer sink
  24  */
  25
  26 #include "libavutil/audio_fifo.h"
  27 #include "libavutil/avassert.h"
  28 #include "libavutil/channel_layout.h"
  29 #include "libavutil/common.h"
  30 #include "libavutil/mathematics.h"
  31
  32 #include "audio.h"
  33 #include "avfilter.h"
  34 #include "buffersink.h"
  35 #include "internal.h"
  36
  37 typedef struct {
  38     AVFrame *cur_frame;          ///< last frame delivered on the sink
  39     AVAudioFifo  *audio_fifo;    ///< FIFO for audio samples
  40     int64_t next_pts;            ///< interpolating audio pts
  41 } BufferSinkContext;
  42
  43 static av_cold void uninit(AVFilterContext *ctx)
  44 {
  45     BufferSinkContext *sink = ctx->priv;
  46
  47     if (sink->audio_fifo)
  48         av_audio_fifo_free(sink->audio_fifo);
  49 }
  50
  51 static int filter_frame(AVFilterLink *link, AVFrame *frame)
  52 {
  53     BufferSinkContext *s = link->dst->priv;
  54
  55     av_assert0(!s->cur_frame);
  56     s->cur_frame = frame;
  57
  58     return 0;
  59 }
  60
  61 int av_buffersink_get_frame(AVFilterContext *ctx, AVFrame *frame)
  62 {
  63     BufferSinkContext *s    = ctx->priv;
  64     AVFilterLink      *link = ctx->inputs[0];
  65     int ret;
  66
  67     if ((ret = ff_request_frame(link)) < 0)
  68         return ret;
  69
  70     if (!s->cur_frame)
  71         return AVERROR(EINVAL);
  72
  73     av_frame_move_ref(frame, s->cur_frame);
  74     av_frame_free(&s->cur_frame);
  75
  76     return 0;
  77 }
  78
  79 static int read_from_fifo(AVFilterContext *ctx, AVFrame *frame,
  80                           int nb_samples)
  81 {
  82     BufferSinkContext *s = ctx->priv;
  83     AVFilterLink   *link = ctx->inputs[0];
  84     AVFrame *tmp;
  85
  86     if (!(tmp = ff_get_audio_buffer(link, nb_samples)))
  87         return AVERROR(ENOMEM);
  88     av_audio_fifo_read(s->audio_fifo, (void**)tmp->extended_data, nb_samples);
  89
  90     tmp->pts = s->next_pts;
  91     s->next_pts += av_rescale_q(nb_samples, (AVRational){1, link->sample_rate},
  92                                 link->time_base);
  93
  94     av_frame_move_ref(frame, tmp);
  95     av_frame_free(&tmp);
  96
  97     return 0;
  98
  99 }
 100
 101 int av_buffersink_get_samples(AVFilterContext *ctx, AVFrame *frame, int nb_samples)
 102 {
 103     BufferSinkContext *s = ctx->priv;
 104     AVFilterLink   *link = ctx->inputs[0];
 105     int ret = 0;
 106
 107     if (!s->audio_fifo) {
 108         int nb_channels = av_get_channel_layout_nb_channels(link->channel_layout);
 109         if (!(s->audio_fifo = av_audio_fifo_alloc(link->format, nb_channels, nb_samples)))
 110             return AVERROR(ENOMEM);
 111     }
 112
 113     while (ret >= 0) {
 114         if (av_audio_fifo_size(s->audio_fifo) >= nb_samples)
 115             return read_from_fifo(ctx, frame, nb_samples);
 116
 117         ret = ff_request_frame(link);
 118         if (ret == AVERROR_EOF && av_audio_fifo_size(s->audio_fifo))
 119             return read_from_fifo(ctx, frame, av_audio_fifo_size(s->audio_fifo));
 120         else if (ret < 0)
 121             return ret;
 122
 123         if (s->cur_frame->pts != AV_NOPTS_VALUE) {
 124             s->next_pts = s->cur_frame->pts -
 125                           av_rescale_q(av_audio_fifo_size(s->audio_fifo),
 126                                        (AVRational){ 1, link->sample_rate },
 127                                        link->time_base);
 128         }
 129
 130         ret = av_audio_fifo_write(s->audio_fifo, (void**)s->cur_frame->extended_data,
 131                                   s->cur_frame->nb_samples);
 132         av_frame_free(&s->cur_frame);
 133     }
 134
 135     return ret;
 136
 137 }
 138
 139 #if FF_API_AVFILTERBUFFER
 140 static void compat_free_buffer(AVFilterBuffer *buf)
 141 {
 142     AVFrame *frame = buf->priv;
 143     av_frame_free(&frame);
 144     av_free(buf);
 145 }
 146
 147 static int compat_read(AVFilterContext *ctx, AVFilterBufferRef **pbuf, int nb_samples)
 148 {
 149     AVFilterBufferRef *buf;
 150     AVFrame *frame;
 151     int ret;
 152
 153     if (!pbuf)
 154         return ff_poll_frame(ctx->inputs[0]);
 155
 156     frame = av_frame_alloc();
 157     if (!frame)
 158         return AVERROR(ENOMEM);
 159
 160     if (!nb_samples)
 161         ret = av_buffersink_get_frame(ctx, frame);
 162     else
 163         ret = av_buffersink_get_samples(ctx, frame, nb_samples);
 164
 165     if (ret < 0)
 166         goto fail;
 167
 168     if (ctx->inputs[0]->type == AVMEDIA_TYPE_VIDEO) {
 169         buf = avfilter_get_video_buffer_ref_from_arrays(frame->data, frame->linesize,
 170                                                         AV_PERM_READ,
 171                                                         frame->width, frame->height,
 172                                                         frame->format);
 173     } else {
 174         buf = avfilter_get_audio_buffer_ref_from_arrays(frame->extended_data,
 175                                                         frame->linesize[0], AV_PERM_READ,
 176                                                         frame->nb_samples,
 177                                                         frame->format,
 178                                                         frame->channel_layout);
 179     }
 180     if (!buf) {
 181         ret = AVERROR(ENOMEM);
 182         goto fail;
 183     }
 184
 185     avfilter_copy_frame_props(buf, frame);
 186
 187     buf->buf->priv = frame;
 188     buf->buf->free = compat_free_buffer;
 189
 190     *pbuf = buf;
 191
 192     return 0;
 193 fail:
 194     av_frame_free(&frame);
 195     return ret;
 196 }
 197
 198 int av_buffersink_read(AVFilterContext *ctx, AVFilterBufferRef **buf)
 199 {
 200     return compat_read(ctx, buf, 0);
 201 }
 202
 203 int av_buffersink_read_samples(AVFilterContext *ctx, AVFilterBufferRef **buf,
 204                                int nb_samples)
 205 {
 206     return compat_read(ctx, buf, nb_samples);
 207 }
 208 #endif
 209
 210 static const AVFilterPad avfilter_vsink_buffer_inputs[] = {
 211     {
 212         .name        = "default",
 213         .type        = AVMEDIA_TYPE_VIDEO,
 214         .filter_frame = filter_frame,
 215         .needs_fifo  = 1
 216     },
 217     { NULL }
 218 };
 219
 220 AVFilter avfilter_vsink_buffer = {
 221     .name      = "buffersink",
 222     .description = NULL_IF_CONFIG_SMALL("Buffer video frames, and make them available to the end of the filter graph."),
 223     .priv_size = sizeof(BufferSinkContext),
 224     .uninit    = uninit,
 225
 226     .inputs    = avfilter_vsink_buffer_inputs,
 227     .outputs   = NULL,
 228 };
 229
 230 static const AVFilterPad avfilter_asink_abuffer_inputs[] = {
 231     {
 232         .name           = "default",
 233         .type           = AVMEDIA_TYPE_AUDIO,
 234         .filter_frame   = filter_frame,
 235         .needs_fifo     = 1
 236     },
 237     { NULL }
 238 };
 239
 240 AVFilter avfilter_asink_abuffer = {
 241     .name      = "abuffersink",
 242     .description = NULL_IF_CONFIG_SMALL("Buffer audio frames, and make them available to the end of the filter graph."),
 243     .priv_size = sizeof(BufferSinkContext),
 244     .uninit    = uninit,
 245
 246     .inputs    = avfilter_asink_abuffer_inputs,
 247     .outputs   = NULL,
 248 };