FFmpeg demo 分析之avio_dir_cmd.c

FFmpeg demo 分析之avio_dir_cmd.c

---

int main(int argc, char *argv[])
{
    const char *op = NULL;
    int ret;

    /* 设定 ffmpeg的log等级 */
    av_log_set_level(AV_LOG_DEBUG);

    if (argc < 2) {
        /* 说明该demo的用法 */
        usage(argv[0]);
        return 1;
    }

    /* 初始化网络组件 */
    /* 但此demo并没有使用网络相关的资源 */
    avformat_network_init();

    /* 判断相应cmd的参数个数，以及跳转执行 */
    op = argv[1];
    if (strcmp(op, "list") == 0) {
        if (argc < 3) {
            av_log(NULL, AV_LOG_INFO, "Missing argument for list operation.\n");
            ret = AVERROR(EINVAL);
        } else {
            ret = list_op(argv[2]);
        }
    } else if (strcmp(op, "del") == 0) {
        if (argc < 3) {
            av_log(NULL, AV_LOG_INFO, "Missing argument for del operation.\n");
            ret = AVERROR(EINVAL);
        } else {
            ret = del_op(argv[2]);
        }
    } else if (strcmp(op, "move") == 0) {
        if (argc < 4) {
            av_log(NULL, AV_LOG_INFO, "Missing argument for move operation.\n");
            ret = AVERROR(EINVAL);
        } else {
            ret = move_op(argv[2], argv[3]);
        }
    } else {
        av_log(NULL, AV_LOG_INFO, "Invalid operation %s\n", op);
        ret = AVERROR(EINVAL);
    }

    /* 网络组件反初始化 */
    avformat_network_deinit();

    return ret < 0 ? 1 : 0;
}

/* 实现的完全就是ls/mv/rm的功能 */
static void usage(const char *program_name)
{
    fprintf(stderr, "usage: %s OPERATION entry1 [entry2]\n"
            "API example program to show how to manipulate resources "
            "accessed through AVIOContext.\n"
            "OPERATIONS:\n"
            "list      list content of the directory\n"
            "move      rename content in directory\n"
            "del       delete content in directory\n",
            program_name);
}

static int list_op(const char *input_dir)
{
    AVIODirEntry *entry = NULL;
    AVIODirContext *ctx = NULL;
    int cnt, ret;
    char filemode[4], uid_and_gid[20];

    /* 打开一个目录，并返回一个AVIODirContext */
    if ((ret = avio_open_dir(&ctx, input_dir, NULL)) < 0) {
        av_log(NULL, AV_LOG_ERROR, "Cannot open directory: %s.\n", av_err2str(ret));
        goto fail;
    }

    /* 遍历整个目录中的文件 */
    cnt = 0;
    for (;;) {
        /* 打开目录 */
        if ((ret = avio_read_dir(ctx, &entry)) < 0) {
            av_log(NULL, AV_LOG_ERROR, "Cannot list directory: %s.\n", av_err2str(ret));
            goto fail;
        }
        /* 为空则表示遍历完整个目录 */
        if (!entry)
            break;
        if (entry->filemode == -1) {
            snprintf(filemode, 4, "???");
        } else {
            snprintf(filemode, 4, "%3"PRIo64, entry->filemode);
        }
        /* 输出文件的相关信息 */
        snprintf(uid_and_gid, 20, "%"PRId64"(%"PRId64")", entry->user_id, entry->group_id);
        if (cnt == 0)
            av_log(NULL, AV_LOG_INFO, "%-9s %12s %30s %10s %s %16s %16s %16s\n",
                   "TYPE", "SIZE", "NAME", "UID(GID)", "UGO", "MODIFIED",
                   "ACCESSED", "STATUS_CHANGED");
        av_log(NULL, AV_LOG_INFO, "%-9s %12"PRId64" %30s %10s %s %16"PRId64" %16"PRId64" %16"PRId64"\n",
               type_string(entry->type),
               entry->size,
               entry->name,
               uid_and_gid,
               filemode,
               entry->modification_timestamp,
               entry->access_timestamp,
               entry->status_change_timestamp);
        /* 释放读取到的entry */
        avio_free_directory_entry(&entry);
        cnt++;
    };

  fail:
    /* 关闭目录 */
    avio_close_dir(&ctx);
    return ret;
}

/* 输出相应类型的字串 */
static const char *type_string(int type)
{
    switch (type) {
    case AVIO_ENTRY_DIRECTORY:
        return "";
    case AVIO_ENTRY_FILE:
        return "";
    case AVIO_ENTRY_BLOCK_DEVICE:
        return "";
    case AVIO_ENTRY_CHARACTER_DEVICE:
        return "";
    case AVIO_ENTRY_NAMED_PIPE:
        return "";
    case AVIO_ENTRY_SYMBOLIC_LINK:
        return "";
    case AVIO_ENTRY_SOCKET:
        return "";
    case AVIO_ENTRY_SERVER:
        return "";
    case AVIO_ENTRY_SHARE:
        return "";
    case AVIO_ENTRY_WORKGROUP:
        return "";
    case AVIO_ENTRY_UNKNOWN:
    default:
        break;
    }
    return "";
}

/* 删除某个文件 */
static int del_op(const char *url)
{
    int ret = avpriv_io_delete(url);
    if (ret < 0)
        av_log(NULL, AV_LOG_ERROR, "Cannot delete '%s': %s.\n", url, av_err2str(ret));
    return ret;
}

/* 移动某个文件 */
static int move_op(const char *src, const char *dst)
{
    int ret = avpriv_io_move(src, dst);
    if (ret < 0)
        av_log(NULL, AV_LOG_ERROR, "Cannot move '%s' into '%s': %s.\n", src, dst, av_err2str(ret));
    return ret;
}