-/**
- * 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);
-}
-