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Diffstat (limited to 'ffmpeg/libavresample/utils.c')
-rw-r--r--ffmpeg/libavresample/utils.c635
1 files changed, 635 insertions, 0 deletions
diff --git a/ffmpeg/libavresample/utils.c b/ffmpeg/libavresample/utils.c
new file mode 100644
index 0000000..c159e33
--- /dev/null
+++ b/ffmpeg/libavresample/utils.c
@@ -0,0 +1,635 @@
+/*
+ * Copyright (c) 2012 Justin Ruggles <justin.ruggles@gmail.com>
+ *
+ * This file is part of Libav.
+ *
+ * Libav is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * Libav is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "libavutil/common.h"
+#include "libavutil/dict.h"
+// #include "libavutil/error.h"
+#include "libavutil/log.h"
+#include "libavutil/mem.h"
+#include "libavutil/opt.h"
+
+#include "avresample.h"
+#include "internal.h"
+#include "audio_data.h"
+#include "audio_convert.h"
+#include "audio_mix.h"
+#include "resample.h"
+
+int avresample_open(AVAudioResampleContext *avr)
+{
+ int ret;
+
+ /* set channel mixing parameters */
+ avr->in_channels = av_get_channel_layout_nb_channels(avr->in_channel_layout);
+ if (avr->in_channels <= 0 || avr->in_channels > AVRESAMPLE_MAX_CHANNELS) {
+ av_log(avr, AV_LOG_ERROR, "Invalid input channel layout: %"PRIu64"\n",
+ avr->in_channel_layout);
+ return AVERROR(EINVAL);
+ }
+ avr->out_channels = av_get_channel_layout_nb_channels(avr->out_channel_layout);
+ if (avr->out_channels <= 0 || avr->out_channels > AVRESAMPLE_MAX_CHANNELS) {
+ av_log(avr, AV_LOG_ERROR, "Invalid output channel layout: %"PRIu64"\n",
+ avr->out_channel_layout);
+ return AVERROR(EINVAL);
+ }
+ avr->resample_channels = FFMIN(avr->in_channels, avr->out_channels);
+ avr->downmix_needed = avr->in_channels > avr->out_channels;
+ avr->upmix_needed = avr->out_channels > avr->in_channels ||
+ (!avr->downmix_needed && (avr->mix_matrix ||
+ avr->in_channel_layout != avr->out_channel_layout));
+ avr->mixing_needed = avr->downmix_needed || avr->upmix_needed;
+
+ /* set resampling parameters */
+ avr->resample_needed = avr->in_sample_rate != avr->out_sample_rate ||
+ avr->force_resampling;
+
+ /* select internal sample format if not specified by the user */
+ if (avr->internal_sample_fmt == AV_SAMPLE_FMT_NONE &&
+ (avr->mixing_needed || avr->resample_needed)) {
+ enum AVSampleFormat in_fmt = av_get_planar_sample_fmt(avr->in_sample_fmt);
+ enum AVSampleFormat out_fmt = av_get_planar_sample_fmt(avr->out_sample_fmt);
+ int max_bps = FFMAX(av_get_bytes_per_sample(in_fmt),
+ av_get_bytes_per_sample(out_fmt));
+ if (max_bps <= 2) {
+ avr->internal_sample_fmt = AV_SAMPLE_FMT_S16P;
+ } else if (avr->mixing_needed) {
+ avr->internal_sample_fmt = AV_SAMPLE_FMT_FLTP;
+ } else {
+ if (max_bps <= 4) {
+ if (in_fmt == AV_SAMPLE_FMT_S32P ||
+ out_fmt == AV_SAMPLE_FMT_S32P) {
+ if (in_fmt == AV_SAMPLE_FMT_FLTP ||
+ out_fmt == AV_SAMPLE_FMT_FLTP) {
+ /* if one is s32 and the other is flt, use dbl */
+ avr->internal_sample_fmt = AV_SAMPLE_FMT_DBLP;
+ } else {
+ /* if one is s32 and the other is s32, s16, or u8, use s32 */
+ avr->internal_sample_fmt = AV_SAMPLE_FMT_S32P;
+ }
+ } else {
+ /* if one is flt and the other is flt, s16 or u8, use flt */
+ avr->internal_sample_fmt = AV_SAMPLE_FMT_FLTP;
+ }
+ } else {
+ /* if either is dbl, use dbl */
+ avr->internal_sample_fmt = AV_SAMPLE_FMT_DBLP;
+ }
+ }
+ av_log(avr, AV_LOG_DEBUG, "Using %s as internal sample format\n",
+ av_get_sample_fmt_name(avr->internal_sample_fmt));
+ }
+
+ /* treat all mono as planar for easier comparison */
+ if (avr->in_channels == 1)
+ avr->in_sample_fmt = av_get_planar_sample_fmt(avr->in_sample_fmt);
+ if (avr->out_channels == 1)
+ avr->out_sample_fmt = av_get_planar_sample_fmt(avr->out_sample_fmt);
+
+ /* we may need to add an extra conversion in order to remap channels if
+ the output format is not planar */
+ if (avr->use_channel_map && !avr->mixing_needed && !avr->resample_needed &&
+ !av_sample_fmt_is_planar(avr->out_sample_fmt)) {
+ avr->internal_sample_fmt = av_get_planar_sample_fmt(avr->out_sample_fmt);
+ }
+
+ /* set sample format conversion parameters */
+ if (avr->resample_needed || avr->mixing_needed)
+ avr->in_convert_needed = avr->in_sample_fmt != avr->internal_sample_fmt;
+ else
+ avr->in_convert_needed = avr->use_channel_map &&
+ !av_sample_fmt_is_planar(avr->out_sample_fmt);
+
+ if (avr->resample_needed || avr->mixing_needed || avr->in_convert_needed)
+ avr->out_convert_needed = avr->internal_sample_fmt != avr->out_sample_fmt;
+ else
+ avr->out_convert_needed = avr->in_sample_fmt != avr->out_sample_fmt;
+
+ avr->in_copy_needed = !avr->in_convert_needed && (avr->mixing_needed ||
+ (avr->use_channel_map && avr->resample_needed));
+
+ if (avr->use_channel_map) {
+ if (avr->in_copy_needed) {
+ avr->remap_point = REMAP_IN_COPY;
+ av_dlog(avr, "remap channels during in_copy\n");
+ } else if (avr->in_convert_needed) {
+ avr->remap_point = REMAP_IN_CONVERT;
+ av_dlog(avr, "remap channels during in_convert\n");
+ } else if (avr->out_convert_needed) {
+ avr->remap_point = REMAP_OUT_CONVERT;
+ av_dlog(avr, "remap channels during out_convert\n");
+ } else {
+ avr->remap_point = REMAP_OUT_COPY;
+ av_dlog(avr, "remap channels during out_copy\n");
+ }
+
+#ifdef DEBUG
+ {
+ int ch;
+ av_dlog(avr, "output map: ");
+ if (avr->ch_map_info.do_remap)
+ for (ch = 0; ch < avr->in_channels; ch++)
+ av_dlog(avr, " % 2d", avr->ch_map_info.channel_map[ch]);
+ else
+ av_dlog(avr, "n/a");
+ av_dlog(avr, "\n");
+ av_dlog(avr, "copy map: ");
+ if (avr->ch_map_info.do_copy)
+ for (ch = 0; ch < avr->in_channels; ch++)
+ av_dlog(avr, " % 2d", avr->ch_map_info.channel_copy[ch]);
+ else
+ av_dlog(avr, "n/a");
+ av_dlog(avr, "\n");
+ av_dlog(avr, "zero map: ");
+ if (avr->ch_map_info.do_zero)
+ for (ch = 0; ch < avr->in_channels; ch++)
+ av_dlog(avr, " % 2d", avr->ch_map_info.channel_zero[ch]);
+ else
+ av_dlog(avr, "n/a");
+ av_dlog(avr, "\n");
+ av_dlog(avr, "input map: ");
+ for (ch = 0; ch < avr->in_channels; ch++)
+ av_dlog(avr, " % 2d", avr->ch_map_info.input_map[ch]);
+ av_dlog(avr, "\n");
+ }
+#endif
+ } else
+ avr->remap_point = REMAP_NONE;
+
+ /* allocate buffers */
+ if (avr->in_copy_needed || avr->in_convert_needed) {
+ avr->in_buffer = ff_audio_data_alloc(FFMAX(avr->in_channels, avr->out_channels),
+ 0, avr->internal_sample_fmt,
+ "in_buffer");
+ if (!avr->in_buffer) {
+ ret = AVERROR(EINVAL);
+ goto error;
+ }
+ }
+ if (avr->resample_needed) {
+ avr->resample_out_buffer = ff_audio_data_alloc(avr->out_channels,
+ 0, avr->internal_sample_fmt,
+ "resample_out_buffer");
+ if (!avr->resample_out_buffer) {
+ ret = AVERROR(EINVAL);
+ goto error;
+ }
+ }
+ if (avr->out_convert_needed) {
+ avr->out_buffer = ff_audio_data_alloc(avr->out_channels, 0,
+ avr->out_sample_fmt, "out_buffer");
+ if (!avr->out_buffer) {
+ ret = AVERROR(EINVAL);
+ goto error;
+ }
+ }
+ avr->out_fifo = av_audio_fifo_alloc(avr->out_sample_fmt, avr->out_channels,
+ 1024);
+ if (!avr->out_fifo) {
+ ret = AVERROR(ENOMEM);
+ goto error;
+ }
+
+ /* setup contexts */
+ if (avr->in_convert_needed) {
+ avr->ac_in = ff_audio_convert_alloc(avr, avr->internal_sample_fmt,
+ avr->in_sample_fmt, avr->in_channels,
+ avr->in_sample_rate,
+ avr->remap_point == REMAP_IN_CONVERT);
+ if (!avr->ac_in) {
+ ret = AVERROR(ENOMEM);
+ goto error;
+ }
+ }
+ if (avr->out_convert_needed) {
+ enum AVSampleFormat src_fmt;
+ if (avr->in_convert_needed)
+ src_fmt = avr->internal_sample_fmt;
+ else
+ src_fmt = avr->in_sample_fmt;
+ avr->ac_out = ff_audio_convert_alloc(avr, avr->out_sample_fmt, src_fmt,
+ avr->out_channels,
+ avr->out_sample_rate,
+ avr->remap_point == REMAP_OUT_CONVERT);
+ if (!avr->ac_out) {
+ ret = AVERROR(ENOMEM);
+ goto error;
+ }
+ }
+ if (avr->resample_needed) {
+ avr->resample = ff_audio_resample_init(avr);
+ if (!avr->resample) {
+ ret = AVERROR(ENOMEM);
+ goto error;
+ }
+ }
+ if (avr->mixing_needed) {
+ avr->am = ff_audio_mix_alloc(avr);
+ if (!avr->am) {
+ ret = AVERROR(ENOMEM);
+ goto error;
+ }
+ }
+
+ return 0;
+
+error:
+ avresample_close(avr);
+ return ret;
+}
+
+void avresample_close(AVAudioResampleContext *avr)
+{
+ ff_audio_data_free(&avr->in_buffer);
+ ff_audio_data_free(&avr->resample_out_buffer);
+ ff_audio_data_free(&avr->out_buffer);
+ av_audio_fifo_free(avr->out_fifo);
+ avr->out_fifo = NULL;
+ ff_audio_convert_free(&avr->ac_in);
+ ff_audio_convert_free(&avr->ac_out);
+ ff_audio_resample_free(&avr->resample);
+ ff_audio_mix_free(&avr->am);
+ av_freep(&avr->mix_matrix);
+
+ avr->use_channel_map = 0;
+}
+
+void avresample_free(AVAudioResampleContext **avr)
+{
+ if (!*avr)
+ return;
+ avresample_close(*avr);
+ av_opt_free(*avr);
+ av_freep(avr);
+}
+
+static int handle_buffered_output(AVAudioResampleContext *avr,
+ AudioData *output, AudioData *converted)
+{
+ int ret;
+
+ if (!output || av_audio_fifo_size(avr->out_fifo) > 0 ||
+ (converted && output->allocated_samples < converted->nb_samples)) {
+ if (converted) {
+ /* if there are any samples in the output FIFO or if the
+ user-supplied output buffer is not large enough for all samples,
+ we add to the output FIFO */
+ av_dlog(avr, "[FIFO] add %s to out_fifo\n", converted->name);
+ ret = ff_audio_data_add_to_fifo(avr->out_fifo, converted, 0,
+ converted->nb_samples);
+ if (ret < 0)
+ return ret;
+ }
+
+ /* if the user specified an output buffer, read samples from the output
+ FIFO to the user output */
+ if (output && output->allocated_samples > 0) {
+ av_dlog(avr, "[FIFO] read from out_fifo to output\n");
+ av_dlog(avr, "[end conversion]\n");
+ return ff_audio_data_read_from_fifo(avr->out_fifo, output,
+ output->allocated_samples);
+ }
+ } else if (converted) {
+ /* copy directly to output if it is large enough or there is not any
+ data in the output FIFO */
+ av_dlog(avr, "[copy] %s to output\n", converted->name);
+ output->nb_samples = 0;
+ ret = ff_audio_data_copy(output, converted,
+ avr->remap_point == REMAP_OUT_COPY ?
+ &avr->ch_map_info : NULL);
+ if (ret < 0)
+ return ret;
+ av_dlog(avr, "[end conversion]\n");
+ return output->nb_samples;
+ }
+ av_dlog(avr, "[end conversion]\n");
+ return 0;
+}
+
+int attribute_align_arg avresample_convert(AVAudioResampleContext *avr,
+ uint8_t **output, int out_plane_size,
+ int out_samples, uint8_t **input,
+ int in_plane_size, int in_samples)
+{
+ AudioData input_buffer;
+ AudioData output_buffer;
+ AudioData *current_buffer;
+ int ret, direct_output;
+
+ /* reset internal buffers */
+ if (avr->in_buffer) {
+ avr->in_buffer->nb_samples = 0;
+ ff_audio_data_set_channels(avr->in_buffer,
+ avr->in_buffer->allocated_channels);
+ }
+ if (avr->resample_out_buffer) {
+ avr->resample_out_buffer->nb_samples = 0;
+ ff_audio_data_set_channels(avr->resample_out_buffer,
+ avr->resample_out_buffer->allocated_channels);
+ }
+ if (avr->out_buffer) {
+ avr->out_buffer->nb_samples = 0;
+ ff_audio_data_set_channels(avr->out_buffer,
+ avr->out_buffer->allocated_channels);
+ }
+
+ av_dlog(avr, "[start conversion]\n");
+
+ /* initialize output_buffer with output data */
+ direct_output = output && av_audio_fifo_size(avr->out_fifo) == 0;
+ if (output) {
+ ret = ff_audio_data_init(&output_buffer, output, out_plane_size,
+ avr->out_channels, out_samples,
+ avr->out_sample_fmt, 0, "output");
+ if (ret < 0)
+ return ret;
+ output_buffer.nb_samples = 0;
+ }
+
+ if (input) {
+ /* initialize input_buffer with input data */
+ ret = ff_audio_data_init(&input_buffer, input, in_plane_size,
+ avr->in_channels, in_samples,
+ avr->in_sample_fmt, 1, "input");
+ if (ret < 0)
+ return ret;
+ current_buffer = &input_buffer;
+
+ if (avr->upmix_needed && !avr->in_convert_needed && !avr->resample_needed &&
+ !avr->out_convert_needed && direct_output && out_samples >= in_samples) {
+ /* in some rare cases we can copy input to output and upmix
+ directly in the output buffer */
+ av_dlog(avr, "[copy] %s to output\n", current_buffer->name);
+ ret = ff_audio_data_copy(&output_buffer, current_buffer,
+ avr->remap_point == REMAP_OUT_COPY ?
+ &avr->ch_map_info : NULL);
+ if (ret < 0)
+ return ret;
+ current_buffer = &output_buffer;
+ } else if (avr->remap_point == REMAP_OUT_COPY &&
+ (!direct_output || out_samples < in_samples)) {
+ /* if remapping channels during output copy, we may need to
+ * use an intermediate buffer in order to remap before adding
+ * samples to the output fifo */
+ av_dlog(avr, "[copy] %s to out_buffer\n", current_buffer->name);
+ ret = ff_audio_data_copy(avr->out_buffer, current_buffer,
+ &avr->ch_map_info);
+ if (ret < 0)
+ return ret;
+ current_buffer = avr->out_buffer;
+ } else if (avr->in_copy_needed || avr->in_convert_needed) {
+ /* if needed, copy or convert input to in_buffer, and downmix if
+ applicable */
+ if (avr->in_convert_needed) {
+ ret = ff_audio_data_realloc(avr->in_buffer,
+ current_buffer->nb_samples);
+ if (ret < 0)
+ return ret;
+ av_dlog(avr, "[convert] %s to in_buffer\n", current_buffer->name);
+ ret = ff_audio_convert(avr->ac_in, avr->in_buffer,
+ current_buffer);
+ if (ret < 0)
+ return ret;
+ } else {
+ av_dlog(avr, "[copy] %s to in_buffer\n", current_buffer->name);
+ ret = ff_audio_data_copy(avr->in_buffer, current_buffer,
+ avr->remap_point == REMAP_IN_COPY ?
+ &avr->ch_map_info : NULL);
+ if (ret < 0)
+ return ret;
+ }
+ ff_audio_data_set_channels(avr->in_buffer, avr->in_channels);
+ if (avr->downmix_needed) {
+ av_dlog(avr, "[downmix] in_buffer\n");
+ ret = ff_audio_mix(avr->am, avr->in_buffer);
+ if (ret < 0)
+ return ret;
+ }
+ current_buffer = avr->in_buffer;
+ }
+ } else {
+ /* flush resampling buffer and/or output FIFO if input is NULL */
+ if (!avr->resample_needed)
+ return handle_buffered_output(avr, output ? &output_buffer : NULL,
+ NULL);
+ current_buffer = NULL;
+ }
+
+ if (avr->resample_needed) {
+ AudioData *resample_out;
+
+ if (!avr->out_convert_needed && direct_output && out_samples > 0)
+ resample_out = &output_buffer;
+ else
+ resample_out = avr->resample_out_buffer;
+ av_dlog(avr, "[resample] %s to %s\n", current_buffer->name,
+ resample_out->name);
+ ret = ff_audio_resample(avr->resample, resample_out,
+ current_buffer);
+ if (ret < 0)
+ return ret;
+
+ /* if resampling did not produce any samples, just return 0 */
+ if (resample_out->nb_samples == 0) {
+ av_dlog(avr, "[end conversion]\n");
+ return 0;
+ }
+
+ current_buffer = resample_out;
+ }
+
+ if (avr->upmix_needed) {
+ av_dlog(avr, "[upmix] %s\n", current_buffer->name);
+ ret = ff_audio_mix(avr->am, current_buffer);
+ if (ret < 0)
+ return ret;
+ }
+
+ /* if we resampled or upmixed directly to output, return here */
+ if (current_buffer == &output_buffer) {
+ av_dlog(avr, "[end conversion]\n");
+ return current_buffer->nb_samples;
+ }
+
+ if (avr->out_convert_needed) {
+ if (direct_output && out_samples >= current_buffer->nb_samples) {
+ /* convert directly to output */
+ av_dlog(avr, "[convert] %s to output\n", current_buffer->name);
+ ret = ff_audio_convert(avr->ac_out, &output_buffer, current_buffer);
+ if (ret < 0)
+ return ret;
+
+ av_dlog(avr, "[end conversion]\n");
+ return output_buffer.nb_samples;
+ } else {
+ ret = ff_audio_data_realloc(avr->out_buffer,
+ current_buffer->nb_samples);
+ if (ret < 0)
+ return ret;
+ av_dlog(avr, "[convert] %s to out_buffer\n", current_buffer->name);
+ ret = ff_audio_convert(avr->ac_out, avr->out_buffer,
+ current_buffer);
+ if (ret < 0)
+ return ret;
+ current_buffer = avr->out_buffer;
+ }
+ }
+
+ return handle_buffered_output(avr, output ? &output_buffer : NULL,
+ current_buffer);
+}
+
+int avresample_get_matrix(AVAudioResampleContext *avr, double *matrix,
+ int stride)
+{
+ int in_channels, out_channels, i, o;
+
+ if (avr->am)
+ return ff_audio_mix_get_matrix(avr->am, matrix, stride);
+
+ in_channels = av_get_channel_layout_nb_channels(avr->in_channel_layout);
+ out_channels = av_get_channel_layout_nb_channels(avr->out_channel_layout);
+
+ if ( in_channels <= 0 || in_channels > AVRESAMPLE_MAX_CHANNELS ||
+ out_channels <= 0 || out_channels > AVRESAMPLE_MAX_CHANNELS) {
+ av_log(avr, AV_LOG_ERROR, "Invalid channel layouts\n");
+ return AVERROR(EINVAL);
+ }
+
+ if (!avr->mix_matrix) {
+ av_log(avr, AV_LOG_ERROR, "matrix is not set\n");
+ return AVERROR(EINVAL);
+ }
+
+ for (o = 0; o < out_channels; o++)
+ for (i = 0; i < in_channels; i++)
+ matrix[o * stride + i] = avr->mix_matrix[o * in_channels + i];
+
+ return 0;
+}
+
+int avresample_set_matrix(AVAudioResampleContext *avr, const double *matrix,
+ int stride)
+{
+ int in_channels, out_channels, i, o;
+
+ if (avr->am)
+ return ff_audio_mix_set_matrix(avr->am, matrix, stride);
+
+ in_channels = av_get_channel_layout_nb_channels(avr->in_channel_layout);
+ out_channels = av_get_channel_layout_nb_channels(avr->out_channel_layout);
+
+ if ( in_channels <= 0 || in_channels > AVRESAMPLE_MAX_CHANNELS ||
+ out_channels <= 0 || out_channels > AVRESAMPLE_MAX_CHANNELS) {
+ av_log(avr, AV_LOG_ERROR, "Invalid channel layouts\n");
+ return AVERROR(EINVAL);
+ }
+
+ if (avr->mix_matrix)
+ av_freep(&avr->mix_matrix);
+ avr->mix_matrix = av_malloc(in_channels * out_channels *
+ sizeof(*avr->mix_matrix));
+ if (!avr->mix_matrix)
+ return AVERROR(ENOMEM);
+
+ for (o = 0; o < out_channels; o++)
+ for (i = 0; i < in_channels; i++)
+ avr->mix_matrix[o * in_channels + i] = matrix[o * stride + i];
+
+ return 0;
+}
+
+int avresample_set_channel_mapping(AVAudioResampleContext *avr,
+ const int *channel_map)
+{
+ ChannelMapInfo *info = &avr->ch_map_info;
+ int in_channels, ch, i;
+
+ in_channels = av_get_channel_layout_nb_channels(avr->in_channel_layout);
+ if (in_channels <= 0 || in_channels > AVRESAMPLE_MAX_CHANNELS) {
+ av_log(avr, AV_LOG_ERROR, "Invalid input channel layout\n");
+ return AVERROR(EINVAL);
+ }
+
+ memset(info, 0, sizeof(*info));
+ memset(info->input_map, -1, sizeof(info->input_map));
+
+ for (ch = 0; ch < in_channels; ch++) {
+ if (channel_map[ch] >= in_channels) {
+ av_log(avr, AV_LOG_ERROR, "Invalid channel map\n");
+ return AVERROR(EINVAL);
+ }
+ if (channel_map[ch] < 0) {
+ info->channel_zero[ch] = 1;
+ info->channel_map[ch] = -1;
+ info->do_zero = 1;
+ } else if (info->input_map[channel_map[ch]] >= 0) {
+ info->channel_copy[ch] = info->input_map[channel_map[ch]];
+ info->channel_map[ch] = -1;
+ info->do_copy = 1;
+ } else {
+ info->channel_map[ch] = channel_map[ch];
+ info->input_map[channel_map[ch]] = ch;
+ info->do_remap = 1;
+ }
+ }
+ /* Fill-in unmapped input channels with unmapped output channels.
+ This is used when remapping during conversion from interleaved to
+ planar format. */
+ for (ch = 0, i = 0; ch < in_channels && i < in_channels; ch++, i++) {
+ while (ch < in_channels && info->input_map[ch] >= 0)
+ ch++;
+ while (i < in_channels && info->channel_map[i] >= 0)
+ i++;
+ if (ch >= in_channels || i >= in_channels)
+ break;
+ info->input_map[ch] = i;
+ }
+
+ avr->use_channel_map = 1;
+ return 0;
+}
+
+int avresample_available(AVAudioResampleContext *avr)
+{
+ return av_audio_fifo_size(avr->out_fifo);
+}
+
+int avresample_read(AVAudioResampleContext *avr, uint8_t **output, int nb_samples)
+{
+ if (!output)
+ return av_audio_fifo_drain(avr->out_fifo, nb_samples);
+ return av_audio_fifo_read(avr->out_fifo, (void**)output, nb_samples);
+}
+
+unsigned avresample_version(void)
+{
+ return LIBAVRESAMPLE_VERSION_INT;
+}
+
+const char *avresample_license(void)
+{
+#define LICENSE_PREFIX "libavresample license: "
+ return LICENSE_PREFIX FFMPEG_LICENSE + sizeof(LICENSE_PREFIX) - 1;
+}
+
+const char *avresample_configuration(void)
+{
+ return FFMPEG_CONFIGURATION;
+}