On Fri, 18 Apr 2014 11:17:55 +0200
Luca Barbato <[email protected]> wrote:
> ---
>
> - changed the return value of convert_frame
> - added open2
> - documented config (open3?)
>
> How to use the new api (will be put somewhere else
>
> AVAudioResampleContext *avr = avresample_alloc();
> AVFrame *out = av_frame_alloc();
> AVFrame *in;
>
> while (fill_input(in)) {
> ret = avresample_convert_frame(avr, out, in);
> do_stuff(out);
> }
>
> ret = avresample_convert_frame(avr, out, NULL);
>
> do_stuff(out);
The example should consider format changes as well, because most users
are going to use this to convert decoder output into a known format.
> libavresample/avresample.h | 77 +++++++++++++++++++++++++
> libavresample/utils.c | 138
> +++++++++++++++++++++++++++++++++++++++++++++
> libavutil/error.h | 2 +
> 3 files changed, 217 insertions(+)
>
> diff --git a/libavresample/avresample.h b/libavresample/avresample.h
> index 3358628..b598d86 100644
> --- a/libavresample/avresample.h
> +++ b/libavresample/avresample.h
> @@ -96,6 +96,7 @@
> #include "libavutil/avutil.h"
> #include "libavutil/channel_layout.h"
> #include "libavutil/dict.h"
> +#include "libavutil/frame.h"
> #include "libavutil/log.h"
>
> #include "libavresample/version.h"
> @@ -172,6 +173,15 @@ AVAudioResampleContext *avresample_alloc_context(void);
> int avresample_open(AVAudioResampleContext *avr);
>
> /**
> + * Initialize AVAudioResampleContext.
> + *
> + * @param avr audio resample context
> + * @param opts optional configuration.
> + * @return 0 on success, negative AVERROR code on failure
> + */
> +int avresample_open2(AVAudioResampleContext *avr, AVDictionary **opts);
Why? Users of avresample_open() can use the AVOptions API on avr, and
don't need this.
> +/**
> * Check whether an AVAudioResampleContext is open or closed.
> *
> * @param avr AVAudioResampleContext to check
> @@ -410,6 +420,73 @@ int avresample_available(AVAudioResampleContext *avr);
> */
> int avresample_read(AVAudioResampleContext *avr, uint8_t **output, int
> nb_samples);
>
> +
> +
> +/**
> + * Convert the samples in the input AVFrame and write them to the output
> AVFrame.
> + *
> + * Input and output AVFrames must have channel_layout, sample_rate and
> format set.
> + *
> + * The upper bound on the number of output samples is given by
> + * avresample_available() + (avresample_get_delay() + number of input
> samples) *
> + * output sample rate / input sample rate.
Still doesn't specify rounding...
> + *
> + * If the output AVFrame does not have the data pointers allocated a the
> nb_samples
> + * will be set as described above and av_frame_get_buffer() will be called.
> + *
> + * The output AVFrame can be NULL or have fewer allocated samples than
> required.
> + *
> + * In this case, any remaining samples not written to the output will be
> added
> + * to an internal FIFO buffer, to be returned at the next call to this
> function
> + * or to avresample_convert() or to avresample_read().
> + *
> + * If converting sample rate, there may be data remaining in the internal
> + * resampling delay buffer. avresample_get_delay() tells the number of
> + * remaining samples. To get this data as output, call this function or
> + * avresample_convert() with NULL input.
> + *
> + * At the end of the conversion process, there may be data remaining in the
> + * internal FIFO buffer. avresample_available() tells the number of remaining
> + * samples. To get this data as output, either call this function or
> + * avresample_convert() with NULL input or call avresample_read().
> + *
> + * If the AVAudioResampleContext configuration does not match the output and
> + * input AVFrame settings the conversion does not take place and depending on
> + * which AVFrame is not matching AVERROR_OUTPUT_CHANGED,
> AVERROR_INPUT_CHANGED
> + * or AVERROR_OUTPUT_CHANGED|AVERROR_INPUT_CHANGED is returned.
> + *
> + * @see avresample_available()
> + * @see avresample_convert()
> + * @see avresample_read()
> + * @see avresample_get_delay()
> + *
> + * @param avr audio resample context
> + * @param output output AVFrame
> + * @param input input AVFrame
> + * @return 0 on success, AVERROR on failure or nonmatching
> + * configuration.
> + */
> +int avresample_convert_frame(AVAudioResampleContext *avr,
> + AVFrame *output, AVFrame *input);
> +
> +/**
> + * Configure or reconfigure the AVAudioResampleContext using the information
> + * provided by the AVFrames and an optional AVDictionary containing
> additional
> + * resampler options.
> + *
> + * The original resampling context is reset even on failure.
> + * The function calls internally avresample_open2().
> + *
> + * @see avresample_open2();
> + *
> + * @param avr audio resample context
> + * @param output output AVFrame
> + * @param input input AVFrame
> + * @return 0 on success, AVERROR on failure.
> + */
> +int avresample_config(AVAudioResampleContext *avr, AVFrame *out, AVFrame *in,
> + AVDictionary **opts);
> +
> /**
> * @}
> */
> diff --git a/libavresample/utils.c b/libavresample/utils.c
> index 35bee42..08e09d8 100644
> --- a/libavresample/utils.c
> +++ b/libavresample/utils.c
> @@ -21,6 +21,7 @@
> #include "libavutil/common.h"
> #include "libavutil/dict.h"
> #include "libavutil/error.h"
> +#include "libavutil/frame.h"
> #include "libavutil/log.h"
> #include "libavutil/mem.h"
> #include "libavutil/opt.h"
> @@ -506,6 +507,143 @@ int attribute_align_arg
> avresample_convert(AVAudioResampleContext *avr,
> current_buffer);
> }
>
> +int avresample_open2(AVAudioResampleContext *avr, AVDictionary **opts)
> +{
> + int ret;
> +
> + if ((ret = av_opt_set_dict(avr, opts)) < 0)
> + return ret;
> +
> + return avresample_open(avr);
> +}
> +
> +int avresample_config(AVAudioResampleContext *avr, AVFrame *out, AVFrame *in,
> + AVDictionary **opts)
> +{
> + if (avresample_is_open(avr)) {
> + avresample_close(avr);
> + }
> +
> + if (!out || !in)
> + return AVERROR(EINVAL);
> +
> + 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;
> +
> + return avresample_open2(avr, opts);
So avresample_open2() has to randomly change semantics as we add more
stuff to AVFrame that can influence resampler options?
> +}
> +
> +static int config_changed(AVAudioResampleContext *avr,
> + AVFrame *out, AVFrame *in)
> +{
> + int ret = 0;
> +
> + if (in) {
> + if (avr->in_channel_layout != in->channel_layout ||
> + avr->in_sample_rate != in->sample_rate ||
> + avr->in_sample_fmt != in->format) {
> + ret |= AVERROR_INPUT_CHANGED;
> + }
> + }
> +
> + if (out) {
> + if (avr->out_channel_layout != out->channel_layout ||
> + avr->out_sample_rate != out->sample_rate ||
> + avr->out_sample_fmt != out->format) {
> + ret |= AVERROR_OUTPUT_CHANGED;
> + }
> + }
> +
> + return ret;
> +}
> +
> +static inline int convert_frame(AVAudioResampleContext *avr,
> + AVFrame *out, AVFrame *in)
> +{
> + int ret;
> + uint8_t **out_data = NULL, **in_data = NULL;
> + int out_linesize = 0, in_linesize = 0;
> + int out_nb_samples = 0, in_nb_samples = 0;
> +
> + if (out) {
> + out_data = out->extended_data;
> + out_linesize = out->linesize[0];
> + out_nb_samples = out->nb_samples;
> + }
> +
> + if (in) {
> + in_data = in->extended_data;
> + in_linesize = in->linesize[0];
> + in_nb_samples = in->nb_samples;
> + }
> +
> + ret = avresample_convert(avr, out_data, out_linesize,
> + out_nb_samples,
> + in_data, in_linesize,
> + in_nb_samples);
> +
> + if (ret > 0) {
> + out->nb_samples = ret;
> + return 0;
> + }
> +
> + return ret;
> +}
> +
> +static inline int optimal_samples(AVAudioResampleContext *avr,
> + AVFrame *out, AVFrame *in)
> +{
> + return avresample_available(avr) +
> + (avresample_get_delay(avr) + in->nb_samples) *
> + out->sample_rate / in->sample_rate;
> +}
> +
> +static inline int available_samples(AVFrame *out)
> +{
> + int bytes_per_sample = av_get_bytes_per_sample(out->format);
> + int samples = out->linesize[0] / bytes_per_sample;
> +
> + if (av_sample_fmt_is_planar(out->format)) {
> + return samples;
> + } else {
> + int channels =
> av_get_channel_layout_nb_channels(out->channel_layout);
> + return samples / channels;
> + }
> +}
> +
> +int avresample_convert_frame(AVAudioResampleContext *avr,
> + AVFrame *out, AVFrame *in)
> +{
> + int ret, setup = 0;
> +
> + if (!avresample_is_open(avr)) {
> + if ((ret = avresample_config(avr, out, in, NULL)) < 0)
> + return ret;
> + setup = 1;
> + } else {
> + // return as is or reconfigure for input changes?
> + if ((ret = config_changed(avr, out, in)))
> + return ret;
I'd say always return, since the caller has to deal with format changes
anyway.
> + }
> +
> + if (out && !out->linesize[0]) {
> + out->nb_samples = optimal_samples(avr, out, in);
> + if ((ret = av_frame_get_buffer(out, 0)) < 0) {
> + if (setup)
> + avresample_close(avr);
> + return ret;
> + }
> + } else {
> + out->nb_samples = available_samples(out);
> + }
> +
> + return convert_frame(avr, out, in);
> +}
> +
> int avresample_get_matrix(AVAudioResampleContext *avr, double *matrix,
> int stride)
> {
> diff --git a/libavutil/error.h b/libavutil/error.h
> index 268a032..0a95d2e 100644
> --- a/libavutil/error.h
> +++ b/libavutil/error.h
> @@ -60,6 +60,8 @@
> #define AVERROR_BUG (-0x5fb8aabe) ///< Bug detected, please
> report the issue
> #define AVERROR_UNKNOWN (-0x31b4b1ab) ///< Unknown error,
> typically from an external library
> #define AVERROR_EXPERIMENTAL (-0x2bb2afa8) ///< Requested feature is
> flagged experimental. Set strict_std_compliance if you really want to use it.
> +#define AVERROR_INPUT_CHANGED (-0x636e6701) ///< Input changed between
> calls. Reconfiguration is required.
> +#define AVERROR_OUTPUT_CHANGED (-0x636e6702) ///< Output changed between
> calls. Reconfiguration is required.
>
> /**
> * Put a description of the AVERROR code errnum in errbuf.
> --
> 1.8.5.2 (Apple Git-48)
>
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