From 4a6d9312cc1c9d62d66c4def71246d9faae29edb Mon Sep 17 00:00:00 2001
From: zhangmeng <775834166@qq.com>
Date: 星期三, 03 三月 2021 14:26:16 +0800
Subject: [PATCH] environment settings
---
module/VideoPlayer/lib/linux/ffmpeg/share/ffmpeg/examples/encode_audio.c | 238 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 238 insertions(+), 0 deletions(-)
diff --git a/module/VideoPlayer/lib/linux/ffmpeg/share/ffmpeg/examples/encode_audio.c b/module/VideoPlayer/lib/linux/ffmpeg/share/ffmpeg/examples/encode_audio.c
new file mode 100644
index 0000000..ab3586b
--- /dev/null
+++ b/module/VideoPlayer/lib/linux/ffmpeg/share/ffmpeg/examples/encode_audio.c
@@ -0,0 +1,238 @@
+/*
+ * Copyright (c) 2001 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+/**
+ * @file
+ * audio encoding with libavcodec API example.
+ *
+ * @example encode_audio.c
+ */
+
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <libavcodec/avcodec.h>
+
+#include <libavutil/channel_layout.h>
+#include <libavutil/common.h>
+#include <libavutil/frame.h>
+#include <libavutil/samplefmt.h>
+
+/* check that a given sample format is supported by the encoder */
+static int check_sample_fmt(const AVCodec *codec, enum AVSampleFormat sample_fmt)
+{
+ const enum AVSampleFormat *p = codec->sample_fmts;
+
+ while (*p != AV_SAMPLE_FMT_NONE) {
+ if (*p == sample_fmt)
+ return 1;
+ p++;
+ }
+ return 0;
+}
+
+/* just pick the highest supported samplerate */
+static int select_sample_rate(const AVCodec *codec)
+{
+ const int *p;
+ int best_samplerate = 0;
+
+ if (!codec->supported_samplerates)
+ return 44100;
+
+ p = codec->supported_samplerates;
+ while (*p) {
+ if (!best_samplerate || abs(44100 - *p) < abs(44100 - best_samplerate))
+ best_samplerate = *p;
+ p++;
+ }
+ return best_samplerate;
+}
+
+/* select layout with the highest channel count */
+static int select_channel_layout(const AVCodec *codec)
+{
+ const uint64_t *p;
+ uint64_t best_ch_layout = 0;
+ int best_nb_channels = 0;
+
+ if (!codec->channel_layouts)
+ return AV_CH_LAYOUT_STEREO;
+
+ p = codec->channel_layouts;
+ while (*p) {
+ int nb_channels = av_get_channel_layout_nb_channels(*p);
+
+ if (nb_channels > best_nb_channels) {
+ best_ch_layout = *p;
+ best_nb_channels = nb_channels;
+ }
+ p++;
+ }
+ return best_ch_layout;
+}
+
+static void encode(AVCodecContext *ctx, AVFrame *frame, AVPacket *pkt,
+ FILE *output)
+{
+ int ret;
+
+ /* send the frame for encoding */
+ ret = avcodec_send_frame(ctx, frame);
+ if (ret < 0) {
+ fprintf(stderr, "Error sending the frame to the encoder\n");
+ exit(1);
+ }
+
+ /* read all the available output packets (in general there may be any
+ * number of them */
+ while (ret >= 0) {
+ ret = avcodec_receive_packet(ctx, pkt);
+ if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
+ return;
+ else if (ret < 0) {
+ fprintf(stderr, "Error encoding audio frame\n");
+ exit(1);
+ }
+
+ fwrite(pkt->data, 1, pkt->size, output);
+ av_packet_unref(pkt);
+ }
+}
+
+int main(int argc, char **argv)
+{
+ const char *filename;
+ const AVCodec *codec;
+ AVCodecContext *c= NULL;
+ AVFrame *frame;
+ AVPacket *pkt;
+ int i, j, k, ret;
+ FILE *f;
+ uint16_t *samples;
+ float t, tincr;
+
+ if (argc <= 1) {
+ fprintf(stderr, "Usage: %s <output file>\n", argv[0]);
+ return 0;
+ }
+ filename = argv[1];
+
+ /* find the MP2 encoder */
+ codec = avcodec_find_encoder(AV_CODEC_ID_MP2);
+ if (!codec) {
+ fprintf(stderr, "Codec not found\n");
+ exit(1);
+ }
+
+ c = avcodec_alloc_context3(codec);
+ if (!c) {
+ fprintf(stderr, "Could not allocate audio codec context\n");
+ exit(1);
+ }
+
+ /* put sample parameters */
+ c->bit_rate = 64000;
+
+ /* check that the encoder supports s16 pcm input */
+ c->sample_fmt = AV_SAMPLE_FMT_S16;
+ if (!check_sample_fmt(codec, c->sample_fmt)) {
+ fprintf(stderr, "Encoder does not support sample format %s",
+ av_get_sample_fmt_name(c->sample_fmt));
+ exit(1);
+ }
+
+ /* select other audio parameters supported by the encoder */
+ c->sample_rate = select_sample_rate(codec);
+ c->channel_layout = select_channel_layout(codec);
+ c->channels = av_get_channel_layout_nb_channels(c->channel_layout);
+
+ /* open it */
+ if (avcodec_open2(c, codec, NULL) < 0) {
+ fprintf(stderr, "Could not open codec\n");
+ exit(1);
+ }
+
+ f = fopen(filename, "wb");
+ if (!f) {
+ fprintf(stderr, "Could not open %s\n", filename);
+ exit(1);
+ }
+
+ /* packet for holding encoded output */
+ pkt = av_packet_alloc();
+ if (!pkt) {
+ fprintf(stderr, "could not allocate the packet\n");
+ exit(1);
+ }
+
+ /* frame containing input raw audio */
+ frame = av_frame_alloc();
+ if (!frame) {
+ fprintf(stderr, "Could not allocate audio frame\n");
+ exit(1);
+ }
+
+ frame->nb_samples = c->frame_size;
+ frame->format = c->sample_fmt;
+ frame->channel_layout = c->channel_layout;
+
+ /* allocate the data buffers */
+ ret = av_frame_get_buffer(frame, 0);
+ if (ret < 0) {
+ fprintf(stderr, "Could not allocate audio data buffers\n");
+ exit(1);
+ }
+
+ /* encode a single tone sound */
+ t = 0;
+ tincr = 2 * M_PI * 440.0 / c->sample_rate;
+ for (i = 0; i < 200; i++) {
+ /* make sure the frame is writable -- makes a copy if the encoder
+ * kept a reference internally */
+ ret = av_frame_make_writable(frame);
+ if (ret < 0)
+ exit(1);
+ samples = (uint16_t*)frame->data[0];
+
+ for (j = 0; j < c->frame_size; j++) {
+ samples[2*j] = (int)(sin(t) * 10000);
+
+ for (k = 1; k < c->channels; k++)
+ samples[2*j + k] = samples[2*j];
+ t += tincr;
+ }
+ encode(c, frame, pkt, f);
+ }
+
+ /* flush the encoder */
+ encode(c, NULL, pkt, f);
+
+ fclose(f);
+
+ av_frame_free(&frame);
+ av_packet_free(&pkt);
+ avcodec_free_context(&c);
+
+ return 0;
+}
--
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