修改卡顿问题

.idea/gradle.xml

@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
+  <component name="GradleMigrationSettings" migrationVersion="1" />
   <component name="GradleSettings">
     <option name="linkedExternalProjectsSettings">
       <GradleProjectSettings>

.idea/misc.xml

@@ -1,4 +1,3 @@
-<?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
   <component name="ExternalStorageConfigurationManager" enabled="true" />
   <component name="ProjectRootManager" version="2" languageLevel="JDK_17" default="true" project-jdk-name="jbr-17" project-jdk-type="JavaSDK">

app/src/main/cpp/PCode.c

@@ -1,10 +1,11 @@
 
-#include "mbedtls/cipher.h"
-#include "mbedtls/entropy.h"
-#include "mbedtls/ctr_drbg.h"
+extern "C" {
+#include <libavcodec/avcodec.h>
+}
 
-#include <stdio.h>
-#include <string.h>
+#include <iostream>
+#include <vector>
+#include <string>
 
 static void print_hex(const char *title, const unsigned char buf[], size_t len)
 {
@@ -16,8 +17,7 @@ static void print_hex(const char *title, const unsigned char buf[], size_t len)
 }
 
 /*
- * The pre-shared key. Should be generated randomly and be unique to the
- * device/channel/etc. Just used a fixed on here for simplicity.
+ * 建立共享内存通道
  */
 static const unsigned char secret_key[16] = {
         0xf4, 0x82, 0xc6, 0x70, 0x3c, 0xc7, 0x61, 0x0a,
@@ -26,151 +26,81 @@ static const unsigned char secret_key[16] = {
 
 static int pcode(void)
 {
-    /* message that should be protected */
-    const char message[] = "Some things are better left unread";
-    /* metadata transmitted in the clear but authenticated */
-    const char metadata[] = "eg sequence number, routing info";
-    /* ciphertext buffer large enough to hold message + nonce + tag */
-    unsigned char ciphertext[128] = { 0 };
-    int ret;
-
-    printf("\r\n\r\n");
-    print_hex("plaintext message", (unsigned char *) message, sizeof message);
-
-    /*
-     * Setup random number generator
-     * (Note: later this might be done automatically.)
-     */
-    mbedtls_entropy_context entropy;    /* entropy pool for seeding PRNG */
-    mbedtls_ctr_drbg_context drbg;      /* pseudo-random generator */
-
-    mbedtls_entropy_init(&entropy);
-    mbedtls_ctr_drbg_init(&drbg);
-
-    /* Seed the PRNG using the entropy pool, and throw in our secret key as an
-     * additional source of randomness. */
-    ret = mbedtls_ctr_drbg_seed(&drbg, mbedtls_entropy_func, &entropy,
-                                secret_key, sizeof (secret_key));
-    if (ret != 0) {
-        printf("mbedtls_ctr_drbg_init() returned -0x%04X\r\n", -ret);
-        return 1;
+    // 检查输入参数
+    if (argc < 2) {
+        std::cerr << "Usage: " << argv[0] << " <input file>" << std::endl;
+        return -1;
     }
 
-    /*
-     * Setup AES-CCM contex
-     */
-    mbedtls_cipher_context_t ctx;
+    // 0. 注册所有的codecs
+    avcodec_register_all();
 
-    mbedtls_cipher_init(&ctx);
-
-    ret = mbedtls_cipher_setup(&ctx, mbedtls_cipher_info_from_type(MBEDTLS_CIPHER_AES_128_CCM));
-    if (ret != 0) {
-        printf("mbedtls_cipher_setup() returned -0x%04X\r\n", -ret);
-        return 1;
+    // 1. 创建一个AVCodecContext
+    AVCodec* codec;
+    AVCodecContext* codec_ctx;
+    codec = avcodec_find_decoder(AV_CODEC_ID_H264); // 假设视频是H.264编码
+    if (!codec) {
+        std::cerr << "Codec not found" << std::endl;
+        return -1;
     }
+    codec_ctx = avcodec_alloc_context3(codec);
 
-    ret = mbedtls_cipher_setkey(&ctx, secret_key, 8 * sizeof secret_key, MBEDTLS_ENCRYPT);
-    if (ret != 0) {
-        printf("mbedtls_cipher_setkey() returned -0x%04X\r\n", -ret);
-        return 1;
+    // 2. 打开codec
+    if (avcodec_open2(codec_ctx, codec, NULL) < 0) {
+        std::cerr << "Could not open codec" << std::endl;
+        return -1;
     }
 
-    /*
-     * Encrypt-authenticate the message and authenticate additional data
-     *
-     * First generate a random 8-byte nonce.
-     * Put it directly in the output buffer as the recipient will need it.
-     *
-     * Warning: you must never re-use the same (key, nonce) pair. One of the
-     * best ways to ensure this to use a counter for the nonce. However this
-     * means you should save the counter accross rebots, if the key is a
-     * long-term one. The alternative we choose here is to generate the nonce
-     * randomly. However it only works if you have a good source of
-     * randomness.
-     */
-    const size_t nonce_len = 8;
-    mbedtls_ctr_drbg_random(&drbg, ciphertext, nonce_len);
-
-    size_t ciphertext_len = 0;
-    /* Go for a conservative 16-byte (128-bit) tag
-     * and append it to the ciphertext */
-    const size_t tag_len = 16;
-    ret = mbedtls_cipher_auth_encrypt(&ctx, ciphertext, nonce_len,
-                                      (const unsigned char *) metadata, sizeof metadata,
-                                      (const unsigned char *) message, sizeof message,
-                                      ciphertext + nonce_len, &ciphertext_len,
-                                      ciphertext + nonce_len + sizeof message, tag_len );
-    if (ret != 0) {
-        printf("mbedtls_cipher_auth_encrypt() returned -0x%04X\r\n", -ret);
-        return 1;
+    // 3. 打开输入的视频文件
+    AVFormatContext* format_ctx = nullptr;
+    if (avformat_open_input(&format_ctx, argv[1], NULL, NULL) < 0) {
+        std::cerr << "Could not open input file" << std::endl;
+        return -1;
     }
-    ciphertext_len += nonce_len + tag_len;
-
-    /*
-     * The following information should now be transmitted:
-     * - first ciphertext_len bytes of ciphertext buffer
-     * - metadata if not already transmitted elsewhere
-     */
-    print_hex("ciphertext", ciphertext, ciphertext_len);
-
-    /*
-     * Decrypt-authenticate
-     */
-    unsigned char decrypted[128] = { 0 };
-    size_t decrypted_len = 0;
-
-    ret = mbedtls_cipher_setkey(&ctx, secret_key, 8 * sizeof secret_key, MBEDTLS_DECRYPT);
-    if (ret != 0) {
-        printf("mbedtls_cipher_setkey() returned -0x%04X\r\n", -ret);
-        return 1;
+
+    // 4. 检索流信息
+    if (avformat_find_stream_info(format_ctx, NULL) < 0) {
+        std::cerr << "Could not find stream information" << std::endl;
+        return -1;
     }
 
-    ret = mbedtls_cipher_auth_decrypt(&ctx,
-                                      ciphertext, nonce_len,
-                                      (const unsigned char *) metadata, sizeof metadata,
-                                      ciphertext + nonce_len, ciphertext_len - nonce_len - tag_len,
-                                      decrypted, &decrypted_len,
-                                      ciphertext + ciphertext_len - tag_len, tag_len );
-    /* Checking the return code is CRITICAL for security here */
-    if (ret == MBEDTLS_ERR_CIPHER_AUTH_FAILED) {
-        printf("Something bad is happening! Data is not authentic!\r\n");
-        return 1;
+    // 5. 找到视频流
+    int video_stream_idx = -1;
+    for (unsigned i = 0; i < format_ctx->nb_streams; i++) {
+        if (format_ctx->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
+            video_stream_idx = i;
+            break;
+        }
     }
-    if (ret != 0) {
-        printf("mbedtls_cipher_authdecrypt() returned -0x%04X\r\n", -ret);
-        return 1;
+    if (video_stream_idx == -1) {
+        std::cerr << "Could not find a video stream" << std::endl;
+        return -1;
     }
 
-    print_hex("decrypted", decrypted, decrypted_len);
-
-    printf("\r\nDONE\r\n");
-
-    return 0;
-}
+    // 6. 创建一个AVPacket和AVFrame
+    AVPacket packet;
+    AVFrame* frame = av_frame_alloc();
 
-#if defined(TARGET_LIKE_MBED)
-
-#include "mbed-drivers/test_env.h"
-#include "minar/minar.h"
-
-static void run() {
-    MBED_HOSTTEST_TIMEOUT(10);
-    MBED_HOSTTEST_SELECT(default);
-    MBED_HOSTTEST_DESCRIPTION(mbed TLS example authcrypt);
-    MBED_HOSTTEST_START("MBEDTLS_EX_AUTHCRYPT");
-    MBED_HOSTTEST_RESULT(example() == 0);
-}
-
-void app_start(int, char*[]) {
-    /* Use 115200 bps for consistency with other examples */
-    get_stdio_serial().baud(115200);
-    minar::Scheduler::postCallback(mbed::util::FunctionPointer0<void>(run).bind());
-}
+    // 7. 循环读取数据包
+    int ret;
+    while (av_read_frame(format_ctx, &packet) >= 0) {
+        // 解码一个数据包
+        if (packet.stream_index == video_stream_idx) {
+            avcodec_decode_video2(codec_ctx, frame, &ret, &packet);
+            if (ret >= 0) {
+                // 处理解码后的帧
+                // 例如，保存帧到文件或显示
+            }
+        }
+        av_packet_unref(&packet);
+    }
 
-#else
+    // 8. 释放资源
+    av_frame_free(&frame);
+    avcodec_close(codec_ctx);
+    avformat_close_input(&format_ctx);
+    av_free(codec_ctx);
 
-int main() {
-    return example();
+    return 0;
 }
 
-#endif

settings.gradle

@@ -1,5 +1,6 @@
 pluginManagement {
     repositories {
+        maven { url 'https://maven.aliyun.com/repository/public/' }
         google()
         mavenCentral()
         gradlePluginPortal()