git.sesse.net Git - ffmpeg/blob - libavfilter/fifo.c

   1 /*
   2  * Copyright (c) 2007 Bobby Bingham
   3  *
   4  * This file is part of FFmpeg.
   5  *
   6  * FFmpeg 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  * FFmpeg 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 FFmpeg; 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  * FIFO buffering filter
  24  */
  25
  26 #include "libavutil/avassert.h"
  27 #include "libavutil/audioconvert.h"
  28 #include "libavutil/mathematics.h"
  29 #include "libavutil/samplefmt.h"
  30
  31 #include "audio.h"
  32 #include "avfilter.h"
  33 #include "internal.h"
  34 #include "video.h"
  35
  36 typedef struct Buf {
  37     AVFilterBufferRef *buf;
  38     struct Buf        *next;
  39 } Buf;
  40
  41 typedef struct {
  42     Buf  root;
  43     Buf *last;   ///< last buffered frame
  44
  45     /**
  46      * When a specific number of output samples is requested, the partial
  47      * buffer is stored here
  48      */
  49     AVFilterBufferRef *buf_out;
  50     int allocated_samples;      ///< number of samples buf_out was allocated for
  51 } FifoContext;
  52
  53 static av_cold int init(AVFilterContext *ctx, const char *args)
  54 {
  55     FifoContext *fifo = ctx->priv;
  56     fifo->last = &fifo->root;
  57
  58     return 0;
  59 }
  60
  61 static av_cold void uninit(AVFilterContext *ctx)
  62 {
  63     FifoContext *fifo = ctx->priv;
  64     Buf *buf, *tmp;
  65
  66     for (buf = fifo->root.next; buf; buf = tmp) {
  67         tmp = buf->next;
  68         avfilter_unref_bufferp(&buf->buf);
  69         av_free(buf);
  70     }
  71
  72     avfilter_unref_bufferp(&fifo->buf_out);
  73 }
  74
  75 static int add_to_queue(AVFilterLink *inlink, AVFilterBufferRef *buf)
  76 {
  77     FifoContext *fifo = inlink->dst->priv;
  78
  79     inlink->cur_buf = NULL;
  80     fifo->last->next = av_mallocz(sizeof(Buf));
  81     if (!fifo->last->next) {
  82         avfilter_unref_buffer(buf);
  83         return AVERROR(ENOMEM);
  84     }
  85
  86     fifo->last = fifo->last->next;
  87     fifo->last->buf = buf;
  88
  89     return 0;
  90 }
  91
  92 static void queue_pop(FifoContext *s)
  93 {
  94     Buf *tmp = s->root.next->next;
  95     if (s->last == s->root.next)
  96         s->last = &s->root;
  97     av_freep(&s->root.next);
  98     s->root.next = tmp;
  99 }
 100
 101 static int end_frame(AVFilterLink *inlink)
 102 {
 103     return 0;
 104 }
 105
 106 static int draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir)
 107 {
 108     return 0;
 109 }
 110
 111 /**
 112  * Move data pointers and pts offset samples forward.
 113  */
 114 static void buffer_offset(AVFilterLink *link, AVFilterBufferRef *buf,
 115                           int offset)
 116 {
 117     int nb_channels = av_get_channel_layout_nb_channels(link->channel_layout);
 118     int planar = av_sample_fmt_is_planar(link->format);
 119     int planes = planar ? nb_channels : 1;
 120     int block_align = av_get_bytes_per_sample(link->format) * (planar ? 1 : nb_channels);
 121     int i;
 122
 123     av_assert0(buf->audio->nb_samples > offset);
 124
 125     for (i = 0; i < planes; i++)
 126         buf->extended_data[i] += block_align*offset;
 127     if (buf->data != buf->extended_data)
 128         memcpy(buf->data, buf->extended_data,
 129                FFMIN(planes, FF_ARRAY_ELEMS(buf->data)) * sizeof(*buf->data));
 130     buf->linesize[0] -= block_align*offset;
 131     buf->audio->nb_samples -= offset;
 132
 133     if (buf->pts != AV_NOPTS_VALUE) {
 134         buf->pts += av_rescale_q(offset, (AVRational){1, link->sample_rate},
 135                                  link->time_base);
 136     }
 137 }
 138
 139 static int calc_ptr_alignment(AVFilterBufferRef *buf)
 140 {
 141     int planes = av_sample_fmt_is_planar(buf->format) ?
 142                  av_get_channel_layout_nb_channels(buf->audio->channel_layout) : 1;
 143     int min_align = 128;
 144     int p;
 145
 146     for (p = 0; p < planes; p++) {
 147         int cur_align = 128;
 148         while ((intptr_t)buf->extended_data[p] % cur_align)
 149             cur_align >>= 1;
 150         if (cur_align < min_align)
 151             min_align = cur_align;
 152     }
 153     return min_align;
 154 }
 155
 156 static int return_audio_frame(AVFilterContext *ctx)
 157 {
 158     AVFilterLink *link = ctx->outputs[0];
 159     FifoContext *s = ctx->priv;
 160     AVFilterBufferRef *head = s->root.next->buf;
 161     AVFilterBufferRef *buf_out;
 162     int ret;
 163
 164     if (!s->buf_out &&
 165         head->audio->nb_samples >= link->request_samples &&
 166         calc_ptr_alignment(head) >= 32) {
 167         if (head->audio->nb_samples == link->request_samples) {
 168             buf_out = head;
 169             queue_pop(s);
 170         } else {
 171             buf_out = avfilter_ref_buffer(head, AV_PERM_READ);
 172             if (!buf_out)
 173                 return AVERROR(ENOMEM);
 174
 175             buf_out->audio->nb_samples = link->request_samples;
 176             buffer_offset(link, head, link->request_samples);
 177         }
 178     } else {
 179         int nb_channels = av_get_channel_layout_nb_channels(link->channel_layout);
 180
 181         if (!s->buf_out) {
 182             s->buf_out = ff_get_audio_buffer(link, AV_PERM_WRITE,
 183                                              link->request_samples);
 184             if (!s->buf_out)
 185                 return AVERROR(ENOMEM);
 186
 187             s->buf_out->audio->nb_samples = 0;
 188             s->buf_out->pts               = head->pts;
 189             s->allocated_samples          = link->request_samples;
 190         } else if (link->request_samples != s->allocated_samples) {
 191             av_log(ctx, AV_LOG_ERROR, "request_samples changed before the "
 192                    "buffer was returned.\n");
 193             return AVERROR(EINVAL);
 194         }
 195
 196         while (s->buf_out->audio->nb_samples < s->allocated_samples) {
 197             int len = FFMIN(s->allocated_samples - s->buf_out->audio->nb_samples,
 198                             head->audio->nb_samples);
 199
 200             av_samples_copy(s->buf_out->extended_data, head->extended_data,
 201                             s->buf_out->audio->nb_samples, 0, len, nb_channels,
 202                             link->format);
 203             s->buf_out->audio->nb_samples += len;
 204
 205             if (len == head->audio->nb_samples) {
 206                 avfilter_unref_buffer(head);
 207                 queue_pop(s);
 208
 209                 if (!s->root.next &&
 210                     (ret = ff_request_frame(ctx->inputs[0])) < 0) {
 211                     if (ret == AVERROR_EOF) {
 212                         av_samples_set_silence(s->buf_out->extended_data,
 213                                                s->buf_out->audio->nb_samples,
 214                                                s->allocated_samples -
 215                                                s->buf_out->audio->nb_samples,
 216                                                nb_channels, link->format);
 217                         s->buf_out->audio->nb_samples = s->allocated_samples;
 218                         break;
 219                     }
 220                     return ret;
 221                 }
 222                 head = s->root.next->buf;
 223             } else {
 224                 buffer_offset(link, head, len);
 225             }
 226         }
 227         buf_out = s->buf_out;
 228         s->buf_out = NULL;
 229     }
 230     return ff_filter_samples(link, buf_out);
 231 }
 232
 233 static int request_frame(AVFilterLink *outlink)
 234 {
 235     FifoContext *fifo = outlink->src->priv;
 236     int ret = 0;
 237
 238     if (!fifo->root.next) {
 239         if ((ret = ff_request_frame(outlink->src->inputs[0])) < 0)
 240             return ret;
 241     }
 242
 243     /* by doing this, we give ownership of the reference to the next filter,
 244      * so we don't have to worry about dereferencing it ourselves. */
 245     switch (outlink->type) {
 246     case AVMEDIA_TYPE_VIDEO:
 247         if ((ret = ff_start_frame(outlink, fifo->root.next->buf)) < 0 ||
 248             (ret = ff_draw_slice(outlink, 0, outlink->h, 1)) < 0 ||
 249             (ret = ff_end_frame(outlink)) < 0)
 250             return ret;
 251
 252         queue_pop(fifo);
 253         break;
 254     case AVMEDIA_TYPE_AUDIO:
 255         if (outlink->request_samples) {
 256             return return_audio_frame(outlink->src);
 257         } else {
 258             ret = ff_filter_samples(outlink, fifo->root.next->buf);
 259             queue_pop(fifo);
 260         }
 261         break;
 262     default:
 263         return AVERROR(EINVAL);
 264     }
 265
 266     return ret;
 267 }
 268
 269 AVFilter avfilter_vf_fifo = {
 270     .name      = "fifo",
 271     .description = NULL_IF_CONFIG_SMALL("Buffer input images and send them when they are requested."),
 272
 273     .init      = init,
 274     .uninit    = uninit,
 275
 276     .priv_size = sizeof(FifoContext),
 277
 278     .inputs    = (const AVFilterPad[]) {{ .name            = "default",
 279                                           .type            = AVMEDIA_TYPE_VIDEO,
 280                                           .get_video_buffer= ff_null_get_video_buffer,
 281                                           .start_frame     = add_to_queue,
 282                                           .draw_slice      = draw_slice,
 283                                           .end_frame       = end_frame,
 284                                           .rej_perms       = AV_PERM_REUSE2, },
 285                                         { .name = NULL}},
 286     .outputs   = (const AVFilterPad[]) {{ .name            = "default",
 287                                           .type            = AVMEDIA_TYPE_VIDEO,
 288                                           .request_frame   = request_frame, },
 289                                         { .name = NULL}},
 290 };
 291
 292 AVFilter avfilter_af_afifo = {
 293     .name        = "afifo",
 294     .description = NULL_IF_CONFIG_SMALL("Buffer input frames and send them when they are requested."),
 295
 296     .init      = init,
 297     .uninit    = uninit,
 298
 299     .priv_size = sizeof(FifoContext),
 300
 301     .inputs    = (const AVFilterPad[]) {{ .name             = "default",
 302                                           .type             = AVMEDIA_TYPE_AUDIO,
 303                                           .get_audio_buffer = ff_null_get_audio_buffer,
 304                                           .filter_samples   = add_to_queue,
 305                                           .rej_perms        = AV_PERM_REUSE2, },
 306                                         { .name = NULL}},
 307     .outputs   = (const AVFilterPad[]) {{ .name             = "default",
 308                                           .type             = AVMEDIA_TYPE_AUDIO,
 309                                           .request_frame    = request_frame, },
 310                                         { .name = NULL}},
 311 };