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af_pan: use libswr for rematrixing.

This commit is contained in:
Nicolas George 2012-02-16 12:34:39 +01:00
parent 560b224f53
commit a44b510d56
2 changed files with 24 additions and 50 deletions
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3
doc/filters.texi
View File

@ -384,9 +384,6 @@ The channel remapping will be effective if, and only if:
@itemize
@item gain coefficients are zeroes or ones,
@item only one input per channel output,
@item the number of output channels is supported by libswresample (16 at the
moment)
@c if SWR_CH_MAX changes, fix the line above.
@end itemize
If all these conditions are satisfied, the filter will notify the user ("Pure

71
libavfilter/af_pan.c
View File

@ -234,18 +234,29 @@ static int config_props(AVFilterLink *link)
}
}
}
// gains are pure, init the channel mapping
if (pan->pure_gains) {
/* TODO reindent */
// sanity check; can't be done in query_formats since the inlink
// channel layout is unknown at that time
if (pan->nb_input_channels > SWR_CH_MAX) {
if (pan->nb_input_channels > SWR_CH_MAX ||
pan->nb_output_channels > SWR_CH_MAX) {
av_log(ctx, AV_LOG_ERROR,
"libswresample support a maximum of %d channels. "
"Feel free to ask for a higher limit.\n", SWR_CH_MAX);
return AVERROR_PATCHWELCOME;
}
// init libswresample context
pan->swr = swr_alloc_set_opts(pan->swr,
pan->out_channel_layout, link->format, link->sample_rate,
link->channel_layout, link->format, link->sample_rate,
0, ctx);
if (!pan->swr)
return AVERROR(ENOMEM);
// gains are pure, init the channel mapping
if (pan->pure_gains) {
// get channel map from the pure gains
for (i = 0; i < pan->nb_output_channels; i++) {
int ch_id = -1;
@ -258,19 +269,9 @@ static int config_props(AVFilterLink *link)
pan->channel_map[i] = ch_id;
}
// init libswresample context
pan->swr = swr_alloc_set_opts(pan->swr,
pan->out_channel_layout, link->format, link->sample_rate,
link->channel_layout, link->format, link->sample_rate,
0, ctx);
if (!pan->swr)
return AVERROR(ENOMEM);
av_opt_set_int(pan->swr, "icl", pan->out_channel_layout, 0);
av_opt_set_int(pan->swr, "uch", pan->nb_output_channels, 0);
swr_set_channel_mapping(pan->swr, pan->channel_map);
r = swr_init(pan->swr);
if (r < 0)
return r;
} else {
// renormalize
for (i = 0; i < pan->nb_output_channels; i++) {
@ -289,7 +290,16 @@ static int config_props(AVFilterLink *link)
for (j = 0; j < pan->nb_input_channels; j++)
pan->gain.d[i][j] /= t;
}
av_opt_set_int(pan->swr, "icl", link->channel_layout, 0);
av_opt_set_int(pan->swr, "ocl", pan->out_channel_layout, 0);
swr_set_matrix(pan->swr, pan->gain.d[0],
pan->gain.d[1] - pan->gain.d[0]);
}
r = swr_init(pan->swr);
if (r < 0)
return r;
// summary
for (i = 0; i < pan->nb_output_channels; i++) {
cur = buf;
@ -331,30 +341,6 @@ static void filter_samples_channel_mapping(PanContext *pan,
swr_convert(pan->swr, outsamples->data, n, (void *)insamples->data, n);
}
static void filter_samples_panning(PanContext *pan,
AVFilterBufferRef *outsamples,
AVFilterBufferRef *insamples,
int n)
{
int i, o;
/* input */
const int16_t *in = (int16_t *)insamples->data[0];
const int16_t *in_end = in + n * pan->nb_input_channels;
/* output */
int16_t *out = (int16_t *)outsamples->data[0];
for (; in < in_end; in += pan->nb_input_channels) {
for (o = 0; o < pan->nb_output_channels; o++) {
int v = 0;
for (i = 0; i < pan->nb_input_channels; i++)
v += pan->gain.i[o][i] * in[i];
*(out++) = v >> 8;
}
}
}
static void filter_samples(AVFilterLink *inlink, AVFilterBufferRef *insamples)
{
int n = insamples->audio->nb_samples;
@ -379,21 +365,12 @@ static int query_formats(AVFilterContext *ctx)
AVFilterLink *outlink = ctx->outputs[0];
AVFilterFormats *formats;
if (pan->nb_output_channels <= SWR_CH_MAX)
/* TODO reindent */
pan->pure_gains = are_gains_pure(pan);
if (pan->pure_gains) {
/* libswr supports any sample and packing formats */
avfilter_set_common_sample_formats(ctx, avfilter_make_all_formats(AVMEDIA_TYPE_AUDIO));
avfilter_set_common_packing_formats(ctx, avfilter_make_all_packing_formats());
pan->filter_samples = filter_samples_channel_mapping;
} else {
const enum AVSampleFormat sample_fmts[] = {AV_SAMPLE_FMT_S16, -1};
const int packing_fmts[] = {AVFILTER_PACKED, -1};
avfilter_set_common_sample_formats (ctx, avfilter_make_format_list(sample_fmts));
avfilter_set_common_packing_formats(ctx, avfilter_make_format_list(packing_fmts));
pan->filter_samples = filter_samples_panning;
}
// inlink supports any channel layout
formats = avfilter_make_all_channel_layouts();