2 * Copyright (c) 2007 Bobby Bingham
4 * This file is part of FFmpeg.
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.
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.
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
23 * FIFO buffering filter
26 #include "libavutil/avassert.h"
27 #include "libavutil/channel_layout.h"
28 #include "libavutil/common.h"
29 #include "libavutil/mathematics.h"
30 #include "libavutil/samplefmt.h"
42 typedef struct FifoContext {
44 Buf *last; ///< last buffered frame
47 * When a specific number of output samples is requested, the partial
48 * buffer is stored here
51 int allocated_samples; ///< number of samples out was allocated for
54 static av_cold int init(AVFilterContext *ctx)
56 FifoContext *fifo = ctx->priv;
57 fifo->last = &fifo->root;
62 static av_cold void uninit(AVFilterContext *ctx)
64 FifoContext *fifo = ctx->priv;
67 for (buf = fifo->root.next; buf; buf = tmp) {
69 av_frame_free(&buf->frame);
73 av_frame_free(&fifo->out);
76 static int add_to_queue(AVFilterLink *inlink, AVFrame *frame)
78 FifoContext *fifo = inlink->dst->priv;
80 fifo->last->next = av_mallocz(sizeof(Buf));
81 if (!fifo->last->next) {
82 av_frame_free(&frame);
83 return AVERROR(ENOMEM);
86 fifo->last = fifo->last->next;
87 fifo->last->frame = frame;
92 static void queue_pop(FifoContext *s)
94 Buf *tmp = s->root.next->next;
95 if (s->last == s->root.next)
97 av_freep(&s->root.next);
102 * Move data pointers and pts offset samples forward.
104 static void buffer_offset(AVFilterLink *link, AVFrame *frame,
107 int nb_channels = link->channels;
108 int planar = av_sample_fmt_is_planar(link->format);
109 int planes = planar ? nb_channels : 1;
110 int block_align = av_get_bytes_per_sample(link->format) * (planar ? 1 : nb_channels);
113 av_assert0(frame->nb_samples > offset);
115 for (i = 0; i < planes; i++)
116 frame->extended_data[i] += block_align * offset;
117 if (frame->data != frame->extended_data)
118 memcpy(frame->data, frame->extended_data,
119 FFMIN(planes, FF_ARRAY_ELEMS(frame->data)) * sizeof(*frame->data));
120 frame->linesize[0] -= block_align*offset;
121 frame->nb_samples -= offset;
123 if (frame->pts != AV_NOPTS_VALUE) {
124 frame->pts += av_rescale_q(offset, (AVRational){1, link->sample_rate},
129 static int calc_ptr_alignment(AVFrame *frame)
131 int planes = av_sample_fmt_is_planar(frame->format) ?
136 for (p = 0; p < planes; p++) {
138 while ((intptr_t)frame->extended_data[p] % cur_align)
140 if (cur_align < min_align)
141 min_align = cur_align;
146 static int return_audio_frame(AVFilterContext *ctx)
148 AVFilterLink *link = ctx->outputs[0];
149 FifoContext *s = ctx->priv;
150 AVFrame *head = s->root.next ? s->root.next->frame : NULL;
154 /* if head is NULL then we're flushing the remaining samples in out */
155 if (!head && !s->out)
159 head->nb_samples >= link->request_samples &&
160 calc_ptr_alignment(head) >= 32) {
161 if (head->nb_samples == link->request_samples) {
165 out = av_frame_clone(head);
167 return AVERROR(ENOMEM);
169 out->nb_samples = link->request_samples;
170 buffer_offset(link, head, link->request_samples);
173 int nb_channels = link->channels;
176 s->out = ff_get_audio_buffer(link, link->request_samples);
178 return AVERROR(ENOMEM);
180 s->out->nb_samples = 0;
181 s->out->pts = head->pts;
182 s->allocated_samples = link->request_samples;
183 } else if (link->request_samples != s->allocated_samples) {
184 av_log(ctx, AV_LOG_ERROR, "request_samples changed before the "
185 "buffer was returned.\n");
186 return AVERROR(EINVAL);
189 while (s->out->nb_samples < s->allocated_samples) {
193 ret = ff_request_frame(ctx->inputs[0]);
194 if (ret == AVERROR_EOF) {
195 av_samples_set_silence(s->out->extended_data,
197 s->allocated_samples -
199 nb_channels, link->format);
200 s->out->nb_samples = s->allocated_samples;
207 head = s->root.next->frame;
209 len = FFMIN(s->allocated_samples - s->out->nb_samples,
212 av_samples_copy(s->out->extended_data, head->extended_data,
213 s->out->nb_samples, 0, len, nb_channels,
215 s->out->nb_samples += len;
217 if (len == head->nb_samples) {
218 av_frame_free(&head);
221 buffer_offset(link, head, len);
227 return ff_filter_frame(link, out);
230 static int request_frame(AVFilterLink *outlink)
232 FifoContext *fifo = outlink->src->priv;
235 if (!fifo->root.next) {
236 if ((ret = ff_request_frame(outlink->src->inputs[0])) < 0) {
237 if (ret == AVERROR_EOF && outlink->request_samples)
238 return return_audio_frame(outlink->src);
241 if (!fifo->root.next)
245 if (outlink->request_samples) {
246 return return_audio_frame(outlink->src);
248 ret = ff_filter_frame(outlink, fifo->root.next->frame);
255 static const AVFilterPad avfilter_vf_fifo_inputs[] = {
258 .type = AVMEDIA_TYPE_VIDEO,
259 .filter_frame = add_to_queue,
264 static const AVFilterPad avfilter_vf_fifo_outputs[] = {
267 .type = AVMEDIA_TYPE_VIDEO,
268 .request_frame = request_frame,
273 AVFilter ff_vf_fifo = {
275 .description = NULL_IF_CONFIG_SMALL("Buffer input images and send them when they are requested."),
280 .priv_size = sizeof(FifoContext),
282 .inputs = avfilter_vf_fifo_inputs,
283 .outputs = avfilter_vf_fifo_outputs,
286 static const AVFilterPad avfilter_af_afifo_inputs[] = {
289 .type = AVMEDIA_TYPE_AUDIO,
290 .filter_frame = add_to_queue,
295 static const AVFilterPad avfilter_af_afifo_outputs[] = {
298 .type = AVMEDIA_TYPE_AUDIO,
299 .request_frame = request_frame,
304 AVFilter ff_af_afifo = {
306 .description = NULL_IF_CONFIG_SMALL("Buffer input frames and send them when they are requested."),
311 .priv_size = sizeof(FifoContext),
313 .inputs = avfilter_af_afifo_inputs,
314 .outputs = avfilter_af_afifo_outputs,