---
Here the first initial draft of an AVFrame based api for avresample.
What it does:
- Provides a way to configure avr from input and output frames (and a dict for
future proofing)
- Provides a mean convert from AVFrame to AVFrame
- Let you be lazy and just call the convert function and have the
configuration and even the
output frame buffers setup happening in the same functions
What does not do:
- Manage reconfigurations implicitly (avscale would)
- Resize the output frame buffer to be optimal if is already set.
Open question/missing bits:
- It currently sets the output nb_samples but does not reset to the max value
on the next iteration
- Output reconfiguration is gory, Input is not so much, do we want to support
it?
- The patch introduces two AVERRORs, not sure how much reuse would see.
libavresample/utils.c | 87 +++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 87 insertions(+)
diff --git a/libavresample/utils.c b/libavresample/utils.c
index 35bee42..67cc7a5 100644
--- a/libavresample/utils.c
+++ b/libavresample/utils.c
@@ -506,6 +506,93 @@ int attribute_align_arg
avresample_convert(AVAudioResampleContext *avr,
current_buffer);
}
+int avresample_config(AVAudioResampleContext *avr, AVFrame *out, AVFrame *in,
+ AVDictionary **opts)
+{
+ int ret;
+
+ if (avresample_is_open(avr)) {
+ avresample_close(avr);
+ }
+
+ avr->in_channel_layout = in->channel_layout;
+ avr->out_channel_layout = out->channel_layout;
+ avr->in_sample_rate = in->sample_rate;
+ avr->out_sample_rate = out->sample_rate;
+ avr->in_sample_fmt = in->format;
+ avr->out_sample_fmt = out->format;
+
+ if ((ret = av_opt_set_dict(avr, opts)) < 0)
+ return ret;
+
+ return avresample_open(avr);
+}
+
+int config_changed(AVAudioResampleContext *avr, AVFrame *out, AVFrame *in)
+{
+ int ret = 0;
+ if (avr->in_channel_layout != in->channel_layout ||
+ avr->in_sample_rate != in->sample_rate ||
+ avr->in_sample_fmt != in->format) {
+ ret |= AVRESAMPLE_INPUT_CHANGED;
+ }
+
+ if (avr->out_channel_layout != out->channel_layout ||
+ avr->out_sample_rate != out->sample_rate ||
+ avr->out_sample_fmt != out->format) {
+ ret |= AVRESAMPLE_OUTPUT_CHANGED;
+ }
+
+ return ret;
+}
+
+int convert_frame(AVAudioResampleContext *avr, AVFrame *out, AVFrame *in)
+{
+ int out_size, out_linesize, out_channels;
+ int out_samplebytes = av_get_bytes_per_sample(out->format);
+ int ret;
+
+ out_channels = av_get_channel_layout_nb_channels(out->channel_layout);
+
+ ret = avresample_convert(avr, out->extended_data, out->linesize[0],
+ in->nb_samples,
+ in->extended_data, in->linesize[0],
+ in->nb_samples);
+
+ if (ret > 0) {
+ out->nb_samples = ret;
+ return 0;
+ }
+
+ return ret;
+}
+
+int avresample_convert_frame(AVAudioResampleContext *avr,
+ AVFrame *out, AVFrame *in)
+{
+ int ret;
+
+ if (!avresample_is_open(avr)) {
+ if ((ret = avresample_config(avr, out, in, NULL)) < 0)
+ return ret;
+ if ((ret = avresample_open(avr)) < 0)
+ return ret;
+ } else {
+ // return as is or reconfigure for input changes?
+ if ((ret = config_changed(avr, out, in)))
+ return ret;
+ }
+
+ if (!out->linesize[0]) {
+ if ((ret = av_frame_get_buffer(out, 0)) < 0) {
+ avresample_close(avr);
+ return ret;
+ }
+ }
+
+ return convert_frame(avr, out, in);
+}
+
int avresample_get_matrix(AVAudioResampleContext *avr, double *matrix,
int stride)
{
--
1.8.5.2 (Apple Git-48)
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