avfiltergraph: smarter sample format selection.

This commit is contained in:
Anton Khirnov 2012-05-19 09:19:41 +02:00
parent 0629f6128e
commit ccefa89f39

View File

@ -461,6 +461,74 @@ static void swap_channel_layouts(AVFilterGraph *graph)
swap_channel_layouts_on_filter(graph->filters[i]);
}
static void swap_sample_fmts_on_filter(AVFilterContext *filter)
{
AVFilterLink *link = NULL;
int format, bps;
int i, j;
for (i = 0; i < filter->input_count; i++) {
link = filter->inputs[i];
if (link->type == AVMEDIA_TYPE_AUDIO &&
link->out_formats->format_count == 1)
break;
}
if (i == filter->input_count)
return;
format = link->out_formats->formats[0];
bps = av_get_bytes_per_sample(format);
for (i = 0; i < filter->output_count; i++) {
AVFilterLink *outlink = filter->outputs[i];
int best_idx, best_score = INT_MIN;
if (outlink->type != AVMEDIA_TYPE_AUDIO ||
outlink->in_formats->format_count < 2)
continue;
for (j = 0; j < outlink->in_formats->format_count; j++) {
int out_format = outlink->in_formats->formats[j];
int out_bps = av_get_bytes_per_sample(out_format);
int score;
if (av_get_packed_sample_fmt(out_format) == format ||
av_get_planar_sample_fmt(out_format) == format) {
best_idx = j;
break;
}
/* for s32 and float prefer double to prevent loss of information */
if (bps == 4 && out_bps == 8) {
best_idx = j;
break;
}
/* prefer closest higher or equal bps */
score = -abs(out_bps - bps);
if (out_bps >= bps)
score += INT_MAX/2;
if (score > best_score) {
best_score = score;
best_idx = j;
}
}
FFSWAP(int, outlink->in_formats->formats[0],
outlink->in_formats->formats[best_idx]);
}
}
static void swap_sample_fmts(AVFilterGraph *graph)
{
int i;
for (i = 0; i < graph->filter_count; i++)
swap_sample_fmts_on_filter(graph->filters[i]);
}
static int pick_formats(AVFilterGraph *graph)
{
int i, j, ret;
@ -491,8 +559,9 @@ int ff_avfilter_graph_config_formats(AVFilterGraph *graph, AVClass *log_ctx)
* of format conversion inside filters */
reduce_formats(graph);
/* for audio filters, ensure the best sample rate and channel layout
/* for audio filters, ensure the best format, sample rate and channel layout
* is selected */
swap_sample_fmts(graph);
swap_samplerates(graph);
swap_channel_layouts(graph);