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/decode_audio.c |  184 ++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 184 insertions(+), 0 deletions(-)

diff --git a/module/VideoPlayer/lib/linux/ffmpeg/share/ffmpeg/examples/decode_audio.c b/module/VideoPlayer/lib/linux/ffmpeg/share/ffmpeg/examples/decode_audio.c
new file mode 100644
index 0000000..19dcafd
--- /dev/null
+++ b/module/VideoPlayer/lib/linux/ffmpeg/share/ffmpeg/examples/decode_audio.c
@@ -0,0 +1,184 @@
+/*
+ * 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 decoding with libavcodec API example
+ *
+ * @example decode_audio.c
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <libavutil/frame.h>
+#include <libavutil/mem.h>
+
+#include <libavcodec/avcodec.h>
+
+#define AUDIO_INBUF_SIZE 20480
+#define AUDIO_REFILL_THRESH 4096
+
+static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame,
+                   FILE *outfile)
+{
+    int i, ch;
+    int ret, data_size;
+
+    /* send the packet with the compressed data to the decoder */
+    ret = avcodec_send_packet(dec_ctx, pkt);
+    if (ret < 0) {
+        fprintf(stderr, "Error submitting the packet to the decoder\n");
+        exit(1);
+    }
+
+    /* read all the output frames (in general there may be any number of them */
+    while (ret >= 0) {
+        ret = avcodec_receive_frame(dec_ctx, frame);
+        if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
+            return;
+        else if (ret < 0) {
+            fprintf(stderr, "Error during decoding\n");
+            exit(1);
+        }
+        data_size = av_get_bytes_per_sample(dec_ctx->sample_fmt);
+        if (data_size < 0) {
+            /* This should not occur, checking just for paranoia */
+            fprintf(stderr, "Failed to calculate data size\n");
+            exit(1);
+        }
+        for (i = 0; i < frame->nb_samples; i++)
+            for (ch = 0; ch < dec_ctx->channels; ch++)
+                fwrite(frame->data[ch] + data_size*i, 1, data_size, outfile);
+    }
+}
+
+int main(int argc, char **argv)
+{
+    const char *outfilename, *filename;
+    const AVCodec *codec;
+    AVCodecContext *c= NULL;
+    AVCodecParserContext *parser = NULL;
+    int len, ret;
+    FILE *f, *outfile;
+    uint8_t inbuf[AUDIO_INBUF_SIZE + AV_INPUT_BUFFER_PADDING_SIZE];
+    uint8_t *data;
+    size_t   data_size;
+    AVPacket *pkt;
+    AVFrame *decoded_frame = NULL;
+
+    if (argc <= 2) {
+        fprintf(stderr, "Usage: %s <input file> <output file>\n", argv[0]);
+        exit(0);
+    }
+    filename    = argv[1];
+    outfilename = argv[2];
+
+    pkt = av_packet_alloc();
+
+    /* find the MPEG audio decoder */
+    codec = avcodec_find_decoder(AV_CODEC_ID_MP2);
+    if (!codec) {
+        fprintf(stderr, "Codec not found\n");
+        exit(1);
+    }
+
+    parser = av_parser_init(codec->id);
+    if (!parser) {
+        fprintf(stderr, "Parser not found\n");
+        exit(1);
+    }
+
+    c = avcodec_alloc_context3(codec);
+    if (!c) {
+        fprintf(stderr, "Could not allocate audio codec context\n");
+        exit(1);
+    }
+
+    /* open it */
+    if (avcodec_open2(c, codec, NULL) < 0) {
+        fprintf(stderr, "Could not open codec\n");
+        exit(1);
+    }
+
+    f = fopen(filename, "rb");
+    if (!f) {
+        fprintf(stderr, "Could not open %s\n", filename);
+        exit(1);
+    }
+    outfile = fopen(outfilename, "wb");
+    if (!outfile) {
+        av_free(c);
+        exit(1);
+    }
+
+    /* decode until eof */
+    data      = inbuf;
+    data_size = fread(inbuf, 1, AUDIO_INBUF_SIZE, f);
+
+    while (data_size > 0) {
+        if (!decoded_frame) {
+            if (!(decoded_frame = av_frame_alloc())) {
+                fprintf(stderr, "Could not allocate audio frame\n");
+                exit(1);
+            }
+        }
+
+        ret = av_parser_parse2(parser, c, &pkt->data, &pkt->size,
+                               data, data_size,
+                               AV_NOPTS_VALUE, AV_NOPTS_VALUE, 0);
+        if (ret < 0) {
+            fprintf(stderr, "Error while parsing\n");
+            exit(1);
+        }
+        data      += ret;
+        data_size -= ret;
+
+        if (pkt->size)
+            decode(c, pkt, decoded_frame, outfile);
+
+        if (data_size < AUDIO_REFILL_THRESH) {
+            memmove(inbuf, data, data_size);
+            data = inbuf;
+            len = fread(data + data_size, 1,
+                        AUDIO_INBUF_SIZE - data_size, f);
+            if (len > 0)
+                data_size += len;
+        }
+    }
+
+    /* flush the decoder */
+    pkt->data = NULL;
+    pkt->size = 0;
+    decode(c, pkt, decoded_frame, outfile);
+
+    fclose(outfile);
+    fclose(f);
+
+    avcodec_free_context(&c);
+    av_parser_close(parser);
+    av_frame_free(&decoded_frame);
+    av_packet_free(&pkt);
+
+    return 0;
+}

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