/* * 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 */ /** * @file * FIFO buffering filter */ #include "libavutil/avassert.h"#include "libavutil/channel_layout.h"#include "libavutil/common.h"#include "libavutil/mathematics.h"#include "libavutil/samplefmt.h" #include "audio.h"#include "avfilter.h"#include "internal.h"#include "video.h" typedef struct Buf {    AVFrame *frame;    struct Buf        *next;} Buf; typedef struct FifoContext {    Buf  root;    Buf *last;   ///< last buffered frame     /**     * When a specific number of output samples is requested, the partial     * buffer is stored here     */    AVFrame *out;    int allocated_samples;      ///< number of samples out was allocated for} FifoContext; static av_cold int init(AVFilterContext *ctx){    FifoContext *fifo = ctx->priv;    fifo->last = &fifo->root;     return 0;} static av_cold void uninit(AVFilterContext *ctx){    FifoContext *fifo = ctx->priv;    Buf *buf, *tmp;     for (buf = fifo->root.next; buf; buf = tmp) {        tmp = buf->next;        av_frame_free(&buf->frame);        av_free(buf);    }     av_frame_free(&fifo->out);} static int add_to_queue(AVFilterLink *inlink, AVFrame *frame){    FifoContext *fifo = inlink->dst->priv;     fifo->last->next = av_mallocz(sizeof(Buf));    if (!fifo->last->next) {        av_frame_free(&frame);        return AVERROR(ENOMEM);    }     fifo->last = fifo->last->next;    fifo->last->frame = frame;     return 0;} static void queue_pop(FifoContext *s){    Buf *tmp = s->root.next->next;    if (s->last == s->root.next)        s->last = &s->root;    av_freep(&s->root.next);    s->root.next = tmp;} /** * Move data pointers and pts offset samples forward. */static void buffer_offset(AVFilterLink *link, AVFrame *frame,                          int offset){    int nb_channels = link->channels;    int planar = av_sample_fmt_is_planar(link->format);    int planes = planar ? nb_channels : 1;    int block_align = av_get_bytes_per_sample(link->format) * (planar ? 1 : nb_channels);    int i;     av_assert0(frame->nb_samples > offset);     for (i = 0; i < planes; i++)        frame->extended_data[i] += block_align * offset;    if (frame->data != frame->extended_data)        memcpy(frame->data, frame->extended_data,               FFMIN(planes, FF_ARRAY_ELEMS(frame->data)) * sizeof(*frame->data));    frame->linesize[0] -= block_align*offset;    frame->nb_samples -= offset;     if (frame->pts != AV_NOPTS_VALUE) {        frame->pts += av_rescale_q(offset, (AVRational){1, link->sample_rate},                                   link->time_base);    }} static int calc_ptr_alignment(AVFrame *frame){    int planes = av_sample_fmt_is_planar(frame->format) ?                 frame->channels : 1;    int min_align = 128;    int p;     for (p = 0; p < planes; p++) {        int cur_align = 128;        while ((intptr_t)frame->extended_data[p] % cur_align)            cur_align >>= 1;        if (cur_align < min_align)            min_align = cur_align;    }    return min_align;} static int return_audio_frame(AVFilterContext *ctx){    AVFilterLink *link = ctx->outputs[0];    FifoContext *s = ctx->priv;    AVFrame *head = s->root.next ? s->root.next->frame : NULL;    AVFrame *out;    int ret;     /* if head is NULL then we're flushing the remaining samples in out */    if (!head && !s->out)        return AVERROR_EOF;     if (!s->out &&        head->nb_samples >= link->request_samples &&        calc_ptr_alignment(head) >= 32) {        if (head->nb_samples == link->request_samples) {            out = head;            queue_pop(s);        } else {            out = av_frame_clone(head);            if (!out)                return AVERROR(ENOMEM);             out->nb_samples = link->request_samples;            buffer_offset(link, head, link->request_samples);        }    } else {        int nb_channels = link->channels;         if (!s->out) {            s->out = ff_get_audio_buffer(link, link->request_samples);            if (!s->out)                return AVERROR(ENOMEM);             s->out->nb_samples = 0;            s->out->pts                   = head->pts;            s->allocated_samples          = link->request_samples;        } else if (link->request_samples != s->allocated_samples) {            av_log(ctx, AV_LOG_ERROR, "request_samples changed before the "                   "buffer was returned.\n");            return AVERROR(EINVAL);        }         while (s->out->nb_samples < s->allocated_samples) {            int len;             if (!s->root.next) {                ret = ff_request_frame(ctx->inputs[0]);                if (ret == AVERROR_EOF) {                    av_samples_set_silence(s->out->extended_data,                                           s->out->nb_samples,                                           s->allocated_samples -                                           s->out->nb_samples,                                           nb_channels, link->format);                    s->out->nb_samples = s->allocated_samples;                    break;                } else if (ret < 0)                    return ret;                if (!s->root.next)                    return 0;            }            head = s->root.next->frame;             len = FFMIN(s->allocated_samples - s->out->nb_samples,                        head->nb_samples);             av_samples_copy(s->out->extended_data, head->extended_data,                            s->out->nb_samples, 0, len, nb_channels,                            link->format);            s->out->nb_samples += len;             if (len == head->nb_samples) {                av_frame_free(&head);                queue_pop(s);            } else {                buffer_offset(link, head, len);            }        }        out = s->out;        s->out = NULL;    }    return ff_filter_frame(link, out);} static int request_frame(AVFilterLink *outlink){    FifoContext *fifo = outlink->src->priv;    int ret = 0;     if (!fifo->root.next) {        if ((ret = ff_request_frame(outlink->src->inputs[0])) < 0) {            if (ret == AVERROR_EOF && outlink->request_samples)                return return_audio_frame(outlink->src);            return ret;        }        if (!fifo->root.next)            return 0;    }     if (outlink->request_samples) {        return return_audio_frame(outlink->src);    } else {        ret = ff_filter_frame(outlink, fifo->root.next->frame);        queue_pop(fifo);    }     return ret;} static const AVFilterPad avfilter_vf_fifo_inputs[] = {    {        .name             = "default",        .type             = AVMEDIA_TYPE_VIDEO,        .filter_frame     = add_to_queue,    },    { NULL }}; static const AVFilterPad avfilter_vf_fifo_outputs[] = {    {        .name          = "default",        .type          = AVMEDIA_TYPE_VIDEO,        .request_frame = request_frame,    },    { NULL }}; AVFilter ff_vf_fifo = {    .name      = "fifo",    .description = NULL_IF_CONFIG_SMALL("Buffer input images and send them when they are requested."),     .init      = init,    .uninit    = uninit,     .priv_size = sizeof(FifoContext),     .inputs    = avfilter_vf_fifo_inputs,    .outputs   = avfilter_vf_fifo_outputs,}; static const AVFilterPad avfilter_af_afifo_inputs[] = {    {        .name             = "default",        .type             = AVMEDIA_TYPE_AUDIO,        .filter_frame     = add_to_queue,    },    { NULL }}; static const AVFilterPad avfilter_af_afifo_outputs[] = {    {        .name          = "default",        .type          = AVMEDIA_TYPE_AUDIO,        .request_frame = request_frame,    },    { NULL }}; AVFilter ff_af_afifo = {    .name        = "afifo",    .description = NULL_IF_CONFIG_SMALL("Buffer input frames and send them when they are requested."),     .init      = init,    .uninit    = uninit,     .priv_size = sizeof(FifoContext),     .inputs    = avfilter_af_afifo_inputs,    .outputs   = avfilter_af_afifo_outputs,};