获取视频长度

Java

public static native double getVideoLength(String inputPath);

C

jni_video_length.c

#include "com_litongjava_media_NativeMedia.h"
#include <jni.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>

#ifdef _WIN32

#include <windows.h>

#endif

// FFmpeg Headers
#include <libavformat/avformat.h>
#include <libavutil/avutil.h>
#include <libavutil/opt.h>
#include <libavcodec/avcodec.h>
#include <libavutil/channel_layout.h>
#include <libavutil/error.h>
#include <libavutil/mathematics.h>
#include <libavutil/mem.h>
#include <libavutil/samplefmt.h>
#include <libavutil/timestamp.h>
#include <time.h>

// 内联函数：拷贝 AVChannelLayout（忽略 opaque 字段）
inline int av_channel_layout_copy(AVChannelLayout *dst, const AVChannelLayout *src) {
  if (!dst || !src) return AVERROR(EINVAL);
  memcpy(dst, src, sizeof(*dst));
  dst->opaque = NULL; // 简化处理，不复制 opaque 字段
  return 0;
}

typedef struct HlsSession {
  AVFormatContext *ofmt_ctx;    // HLS muxer 输出上下文
  int segDuration;              // 分段时长（秒）
  int nextSegmentNumber;        // 当前下一个分段编号
  int64_t global_offset;        // 全局时间戳偏移量
  char *ts_pattern;             // TS 分段文件命名模板（深拷贝保存）
  int header_written;           // 标识是否已写 header
  AVDictionary *opts;           // 保存 HLS 配置选项
  time_t created_time;          // 会话创建时间
  int closed;         // 0 表示未释放，1 表示已释放
} HlsSession;

typedef struct HlsSessionNode {
  HlsSession *session;
  struct HlsSessionNode *next;
} HlsSessionNode;

// 全局链表头指针，用于维护所有活跃的 HLS 会话
static HlsSessionNode *g_hlsSessionHead = NULL;

// 添加一个会话到全局链表
static void add_hls_session(HlsSession *session) {
  HlsSessionNode *node = (HlsSessionNode *) malloc(sizeof(HlsSessionNode));
  if (node) {
    node->session = session;
    node->next = g_hlsSessionHead;
    g_hlsSessionHead = node;
  }
}

// 从全局链表中删除一个会话
static void remove_hls_session(HlsSession *session) {
  HlsSessionNode **curr = &g_hlsSessionHead;
  while (*curr) {
    if ((*curr)->session == session) {
      HlsSessionNode *tmp = *curr;
      *curr = tmp->next;
      free(tmp);
      return;
    }
    curr = &((*curr)->next);
  }
}

// 辅助函数：查找全局列表中是否存在给定的会话
static HlsSession *find_hls_session(HlsSession *sessionPtrValue) {
  HlsSessionNode *curr = g_hlsSessionHead;
  while (curr) {
    if (curr->session == sessionPtrValue) {
      return curr->session;
    }
    curr = curr->next;
  }
  return NULL;
}

JNIEXPORT jlong JNICALL Java_com_litongjava_media_NativeMedia_initPersistentHls
  (JNIEnv *env, jclass clazz, jstring playlistUrlJ, jstring tsPatternJ, jint startNumber, jint segDuration) {

  const char *playlistUrl = (*env)->GetStringUTFChars(env, playlistUrlJ, NULL);
  const char *tsPattern = (*env)->GetStringUTFChars(env, tsPatternJ, NULL);

  HlsSession *session = (HlsSession *) malloc(sizeof(HlsSession));
  if (!session) {
    (*env)->ReleaseStringUTFChars(env, playlistUrlJ, playlistUrl);
    (*env)->ReleaseStringUTFChars(env, tsPatternJ, tsPattern);
    return 0;
  }
  memset(session, 0, sizeof(HlsSession));
  session->segDuration = segDuration;
  session->nextSegmentNumber = startNumber;
  session->global_offset = 0;
  session->header_written = 0; // header 尚未写入
  session->ts_pattern = strdup(tsPattern);
  if (!session->ts_pattern) {
    free(session);
    (*env)->ReleaseStringUTFChars(env, playlistUrlJ, playlistUrl);
    (*env)->ReleaseStringUTFChars(env, tsPatternJ, tsPattern);
    return 0;
  }
  // 记录会话创建时间
  session->created_time = time(NULL);

  // 创建输出上下文，指定 muxer 为 "hls"，目标为 playlistUrl
  AVFormatContext *ofmt_ctx = NULL;
  int ret = avformat_alloc_output_context2(&ofmt_ctx, NULL, "hls", playlistUrl);
  if (ret < 0 || !ofmt_ctx) {
    free(session->ts_pattern);
    free(session);
    (*env)->ReleaseStringUTFChars(env, playlistUrlJ, playlistUrl);
    (*env)->ReleaseStringUTFChars(env, tsPatternJ, tsPattern);
    return 0;
  }

  // 构造 HLS 选项字典，并保存到 session->opts
  AVDictionary *opts = NULL;
  char seg_time_str[16] = {0};
  snprintf(seg_time_str, sizeof(seg_time_str), "%d", segDuration);
  av_dict_set(&opts, "hls_time", seg_time_str, 0);
  // 使用用户指定的 tsPattern，例如 "segment_video_%03d.ts"
  av_dict_set(&opts, "hls_segment_filename", tsPattern, 0);
  av_dict_set(&opts, "hls_flags", "append_list", 0);
  av_dict_set(&opts, "hls_list_size", "0", 0);
  av_dict_set(&opts, "hls_playlist_type", "event", 0);
  char start_num_str[16] = {0};
  snprintf(start_num_str, sizeof(start_num_str), "%d", startNumber);
  av_dict_set(&opts, "start_number", start_num_str, 0);
  session->opts = opts;

  // 如果输出格式要求打开文件，则调用 avio_open
  if (!(ofmt_ctx->oformat->flags & AVFMT_NOFILE)) {
    ret = avio_open(&ofmt_ctx->pb, playlistUrl, AVIO_FLAG_WRITE);
    if (ret < 0) {
      av_dict_free(&opts);
      avformat_free_context(ofmt_ctx);
      free(session->ts_pattern);
      free(session);
      (*env)->ReleaseStringUTFChars(env, playlistUrlJ, playlistUrl);
      (*env)->ReleaseStringUTFChars(env, tsPatternJ, tsPattern);
      return 0;
    }
  }

  session->ofmt_ctx = ofmt_ctx;

  (*env)->ReleaseStringUTFChars(env, playlistUrlJ, playlistUrl);
  (*env)->ReleaseStringUTFChars(env, tsPatternJ, tsPattern);

  // 加入全局会话列表
  add_hls_session(session);

  return (jlong) session;
}

/*
 * Class:     com_litongjava_media_NativeMedia
 * Method:    finishPersistentHls
 * Signature: (JLjava/lang/String;)Ljava/lang/String;
 *
 * 实现说明：
 * 1. 根据传入的会话指针，取出 HLS 会话结构体；
 * 2. 调用 av_write_trailer 写入 trailer（如生成 EXT‑X‑ENDLIST 标签），关闭输出流；
 * 3. 释放输出上下文以及会话中分配的资源（例如 TS 模板字符串和会话结构体）；
 * 4. 返回结束操作的状态信息。
 */
JNIEXPORT jstring JNICALL Java_com_litongjava_media_NativeMedia_finishPersistentHls
  (JNIEnv *env, jclass clazz, jlong sessionPtr, jstring playlistUrlJ) {

  // 将 sessionPtr 转换为 HlsSession 指针
  HlsSession *sessionInput = (HlsSession *) (uintptr_t) sessionPtr;
  // 通过全局列表查找该会话是否还存活
  HlsSession *session = find_hls_session(sessionInput);
  if (!session) {
    return (*env)->NewStringUTF(env, "Session already freed");
  }

  // 如果已经关闭，则直接返回
  if (session->closed) {
    return (*env)->NewStringUTF(env, "Session already freed");
  }

  // 从 Java 字符串中获取播放列表路径（用于返回消息）
  const char *playlistUrl = (*env)->GetStringUTFChars(env, playlistUrlJ, NULL);

  // 写入 trailer，结束会话
  int ret = av_write_trailer(session->ofmt_ctx);
  if (ret < 0) {
    (*env)->ReleaseStringUTFChars(env, playlistUrlJ, playlistUrl);
    // 如果写 trailer 出错，也应关闭资源以避免泄漏
    if (!(session->ofmt_ctx->oformat->flags & AVFMT_NOFILE))
      avio_closep(&session->ofmt_ctx->pb);
    avformat_free_context(session->ofmt_ctx);
    free(session->ts_pattern);
    // 从全局列表中删除该会话
    remove_hls_session(session);
    return (*env)->NewStringUTF(env, "Failed to write trailer");
  }

  // 关闭输出文件（如果必要），并释放输出上下文
  if (!(session->ofmt_ctx->oformat->flags & AVFMT_NOFILE))
    avio_closep(&session->ofmt_ctx->pb);
  avformat_free_context(session->ofmt_ctx);

  // 从全局列表中删除该会话
  remove_hls_session(session);
  // 标记会话状态为已关闭，以防重复释放
  session->closed = 1;
  // 释放会话中分配的资源
  free(session->ts_pattern);
  free(session);

  // 构造返回消息
  char resultMsg[256] = {0};
  snprintf(resultMsg, sizeof(resultMsg),
           "Persistent HLS session finished successfully: playlist %s", playlistUrl);

  (*env)->ReleaseStringUTFChars(env, playlistUrlJ, playlistUrl);
  return (*env)->NewStringUTF(env, resultMsg);
}


JNIEXPORT jstring JNICALL Java_com_litongjava_media_NativeMedia_appendVideoSegmentToHls
  (JNIEnv *env, jclass clazz, jlong sessionPtr, jstring inputFilePathJ) {
  HlsSession *session = (HlsSession *) sessionPtr;
  if (!session || !session->ofmt_ctx) {
    return (*env)->NewStringUTF(env, "Invalid HLS session pointer");
  }

  const char *inputFilePath = (*env)->GetStringUTFChars(env, inputFilePathJ, NULL);
  if (!inputFilePath) {
    return (*env)->NewStringUTF(env, "Failed to get input file path");
  }

  AVFormatContext *ifmt_ctx = NULL;
  int ret = avformat_open_input(&ifmt_ctx, inputFilePath, NULL, NULL);
  if (ret < 0) {
    char errbuf[128] = {0};
    av_strerror(ret, errbuf, sizeof(errbuf));
    (*env)->ReleaseStringUTFChars(env, inputFilePathJ, inputFilePath);
    char msg[256] = {0};
    snprintf(msg, sizeof(msg), "Failed to open input file: %s", errbuf);
    return (*env)->NewStringUTF(env, msg);
  }

  ret = avformat_find_stream_info(ifmt_ctx, NULL);
  if (ret < 0) {
    avformat_close_input(&ifmt_ctx);
    (*env)->ReleaseStringUTFChars(env, inputFilePathJ, inputFilePath);
    return (*env)->NewStringUTF(env, "Failed to retrieve stream info from input file");
  }

  // 如果 persistent HLS 会话中还没有输出流，则首次追加：
  if (session->ofmt_ctx->nb_streams == 0) {
    for (unsigned int i = 0; i < ifmt_ctx->nb_streams; i++) {
      AVStream *in_stream = ifmt_ctx->streams[i];
      if (in_stream->codecpar->codec_type == AVMEDIA_TYPE_VIDEO ||
          in_stream->codecpar->codec_type == AVMEDIA_TYPE_AUDIO) {
        AVStream *out_stream = avformat_new_stream(session->ofmt_ctx, NULL);
        if (!out_stream) continue;
        ret = avcodec_parameters_copy(out_stream->codecpar, in_stream->codecpar);
        if (ret < 0) continue;
        out_stream->codecpar->codec_tag = 0;
        out_stream->time_base = in_stream->time_base;
      }
    }
    // 使用保存的 opts 调用 avformat_write_header
    ret = avformat_write_header(session->ofmt_ctx, &session->opts);
    if (ret < 0) {
      avformat_close_input(&ifmt_ctx);
      (*env)->ReleaseStringUTFChars(env, inputFilePathJ, inputFilePath);
      return (*env)->NewStringUTF(env, "Failed to write header on first segment append");
    }
    session->header_written = 1;
    // 释放 opts 后不再需要
    av_dict_free(&session->opts);
  }

  // 计算输入文件音视频流的最大时长（单位转换为 AV_TIME_BASE）
  int64_t file_duration = 0;
  for (unsigned int i = 0; i < ifmt_ctx->nb_streams; i++) {
    AVStream *in_stream = ifmt_ctx->streams[i];
    if (in_stream->codecpar->codec_type == AVMEDIA_TYPE_VIDEO ||
        in_stream->codecpar->codec_type == AVMEDIA_TYPE_AUDIO) {
      if (in_stream->duration > 0) {
        int64_t dur = av_rescale_q(in_stream->duration, in_stream->time_base, AV_TIME_BASE_Q);
        if (dur > file_duration)
          file_duration = dur;
      }
    }
  }

  AVPacket pkt;
  while (av_read_frame(ifmt_ctx, &pkt) >= 0) {
    AVStream *in_stream = ifmt_ctx->streams[pkt.stream_index];
    if (in_stream->codecpar->codec_type != AVMEDIA_TYPE_VIDEO &&
        in_stream->codecpar->codec_type != AVMEDIA_TYPE_AUDIO) {
      av_packet_unref(&pkt);
      continue;
    }

    // 按流类型匹配：假设只有一个视频流和一个音频流
    int out_index = -1;
    for (unsigned int j = 0; j < session->ofmt_ctx->nb_streams; j++) {
      AVStream *out_stream = session->ofmt_ctx->streams[j];
      if (out_stream->codecpar->codec_type == in_stream->codecpar->codec_type) {
        out_index = j;
        break;
      }
    }
    if (out_index < 0) {
      av_packet_unref(&pkt);
      continue;
    }
    AVStream *out_stream = session->ofmt_ctx->streams[out_index];

    // 将 pkt 时间戳转换后加上全局偏移
    int64_t offset = av_rescale_q(session->global_offset, AV_TIME_BASE_Q, out_stream->time_base);
    pkt.pts = av_rescale_q(pkt.pts, in_stream->time_base, out_stream->time_base) + offset;
    pkt.dts = av_rescale_q(pkt.dts, in_stream->time_base, out_stream->time_base) + offset;
    if (pkt.duration > 0)
      pkt.duration = av_rescale_q(pkt.duration, in_stream->time_base, out_stream->time_base);
    pkt.pos = -1;
    pkt.stream_index = out_index;

    ret = av_interleaved_write_frame(session->ofmt_ctx, &pkt);
    if (ret < 0) {
      av_packet_unref(&pkt);
      break;
    }
    av_packet_unref(&pkt);
  }

  // 累计更新全局时间偏移，确保下一个分段在时间上衔接
  session->global_offset += file_duration;

  avformat_close_input(&ifmt_ctx);
  (*env)->ReleaseStringUTFChars(env, inputFilePathJ, inputFilePath);

  char resultMsg[256] = {0};
  snprintf(resultMsg, sizeof(resultMsg),
           "Appended video segment successfully, updated global offset to %lld", session->global_offset);
  return (*env)->NewStringUTF(env, resultMsg);
}


JNIEXPORT jstring JNICALL Java_com_litongjava_media_NativeMedia_listHlsSession
  (JNIEnv *env, jclass clazz) {
  // 构造 JSON 数组字符串，格式示例：
  // [ {"sessionPtr":123456, "createdTime": "2025-04-12 09:30:00", "globalOffset": 1000}, {...} ]
  char buffer[4096] = {0};
  strcat(buffer, "[");

  HlsSessionNode *curr = g_hlsSessionHead;
  int first = 1;
  char timeStr[64] = {0};
  while (curr) {
    if (!first) {
      strcat(buffer, ",");
    } else {
      first = 0;
    }
    // 格式化创建时间为字符串
    struct tm *tm_info = localtime(&(curr->session->created_time));
    strftime(timeStr, sizeof(timeStr), "%Y-%m-%d %H:%M:%S", tm_info);
    char item[256] = {0};
    snprintf(item, sizeof(item),
             "{\"sessionPtr\":%llu,\"createdTime\":\"%s\",\"globalOffset\":%lld}",
             (unsigned long long) (uintptr_t) curr->session, timeStr, curr->session->global_offset);
    strcat(buffer, item);
    curr = curr->next;
  }
  strcat(buffer, "]");
  return (*env)->NewStringUTF(env, buffer);
}

/* 新增：直接释放 HLS 会话，不需要传递播放列表路径 */
JNIEXPORT jstring JNICALL Java_com_litongjava_media_NativeMedia_freeHlsSession
  (JNIEnv *env, jclass clazz, jlong sessionPtr) {
  // 将 sessionPtr 转换为 HlsSession 指针
  HlsSession *sessionInput = (HlsSession *) (uintptr_t) sessionPtr;
  // 通过全局列表查找该会话是否还存活
  HlsSession *session = find_hls_session(sessionInput);

  if (!session) {
    return (*env)->NewStringUTF(env, "Invalid session pointer");
  }

  // 如果已经关闭了，直接返回
  if (session->closed) {
    return (*env)->NewStringUTF(env, "Session already freed");
  }
  // 如果输出上下文存在且打开了输出文件，则关闭输出文件
  if (session->ofmt_ctx) {
    if (!(session->ofmt_ctx->oformat->flags & AVFMT_NOFILE))
      avio_closep(&session->ofmt_ctx->pb);
    avformat_free_context(session->ofmt_ctx);
  }

  // 从全局会话列表中删除该会话
  remove_hls_session(session);

  // 释放会话结构体中分配的资源
  if (session->ts_pattern)
    free(session->ts_pattern);
  free(session);

  return (*env)->NewStringUTF(env, "HLS session freed successfully");
}

1.学习上面的代码 2.现在请你完成一个新的功能,给视频的右下角添加水印,有水印的视频单独存储 3.注意支持中文