MeowOS-For-R3P2/patch_v2/ncm_app/app/play/audio_out.c

/* play/audio_out.c — 音频输出抽象：默认 SINK_AUDIOD（meow_audiod 独占服务，经 SDK meow_audio_*），
 * 调试保底 SINK_ALSADEV 直开 hw:0,0，另有 FILE/NULL sink。
 *
 * 后端选择（audio_out_open，env 驱动）：
 *   - 缺省              → SINK_AUDIOD（SDK 客户端连 /usr/data/meow_audio.sock；audiod 独占声卡、
 *                         格式归一/采样率跟随/抢占全在服务端，AUDIOD_DESIGN.md §7）。
 *   - NCM_AUDIO_SINK=file/null/alsa → FILE（WAV，NCM_AUDIO_OUT 指定路径，缺省 /tmp/ncm_out.wav）/
 *                         NULL（丢弃，仅测解码 RT）/ ALSA 直开。
 *   - MEOW_AUDIO_DIRECT=1           → ALSA 直开（调试保底，非正式能力，勿依赖）。
 * audiod 不在 → open 返回 -1（不隐式回退直开，AUDIOD_DESIGN.md §7）。
 *
 * ALSA 直开两大坑（真机定位，agent-246，与 audiod/SDK 同款修法，勿回退）：
 *   ① hw_params 须「全放行」初始化（params_any 语义：mask 全 1、interval [0,UINT_MAX]）
 *      ——memset 0 的 interval 等价「只能取 0」→ 内核 refine 必空 → HW_PARAMS 恒 EINVAL；
 *   ② access/format/subformat mask 须先清零再单点（pmask 只 OR）——留全 1 会被 choose 成
 *      MMAP_INTERLEAVED → write() 恒 EINVAL。
 * 注意 musl 的 sound/asound.h 中 masks/intervals 是**重索引**数组：
 *   masks[k] ↔ hw_param (FIRST_MASK + k)；intervals[k] ↔ hw_param (FIRST_INTERVAL + k)。
 *
 * 线程模型：仅由 player_manager 播放线程调用（单写者）；audio_out_close 可被 UI 线程调用打断阻塞写。
 * 日志：open 结果/参数、audiod 授权 grant_*、write 错误、pause/resume/close 全写 meow_log
 * （无声排查的永久资产，勿省）。
 */
#include "../ncm_app_internal.h"
#include "meow_ipc.h"           /* AUDIO_FMT_S16 / MSG_AUDIO_VOLUME / MEOW_IPC_HDR_LEN */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <sys/socket.h>
#include <sys/un.h>

#ifdef __linux__
#include <sound/asound.h>
#include <sys/ioctl.h>
#define NCM_HAVE_ALSA 1
#endif

enum { SINK_AUDIOD = 0, SINK_ALSADEV = 1, SINK_FILE = 2, SINK_NULL = 3 };
static int  g_sink = -1;
static int  g_fd = -1;             /* alsa or file fd */
static int  g_sid = 0;             /* audiod stream id（>0 有效） */
static int  g_rate, g_ch, g_bits;
static const char *g_path = NULL;
static uint64_t g_wr_frames = 0;   /* 本次 open 累计写帧（日志） */
static int      g_wr_errs = 0;     /* 写错误计数（节流日志） */

#define NCM_DEFAULT_OUT "/tmp/ncm_out.wav"

void audio_out_set_target(int ms) { (void)ms; }
int  audio_out_buffered_ms(void) { return 0; }

#ifdef NCM_HAVE_ALSA
/* ALSA 非 mmap 直装：开设备 → hw_params（access=rw_interleaved, S16_LE, rate, ch）→ write。 */
static void pmask(struct snd_mask *m, unsigned bit) { m->bits[bit / 32] |= 1u << (bit % 32); }
static void pivset(struct snd_interval *iv, unsigned val)
{
    iv->min = iv->max = val;
    iv->integer = 1;
    iv->openmin = iv->openmax = 0;
    iv->empty = 0;
}
static int alsa_open(int rate, int ch, int bits)
{
    if (bits != 16 && bits != 32) return -1;   /* §19：S16 + S32（flac >16bit 满幅） */
    int fd = open("/dev/snd/pcmC0D0p", O_RDWR);
    if (fd < 0) {
        meow_log(MEOW_LOG_ERROR, "audio: alsa open /dev/snd/pcmC0D0p failed errno=%d", errno);
        return -1;
    }
    struct snd_pcm_hw_params p;
    /* 坑①：「全放行」初始化（snd_pcm_hw_params_any 语义）：mask 全 1、interval [0,UINT_MAX]。
     * memset 0 的 interval 会被内核当成「只能取 0」约束 → refine 必空 → HW_PARAMS 恒 EINVAL。 */
    memset(&p, 0, sizeof p);
    unsigned nm = SNDRV_PCM_HW_PARAM_LAST_MASK - SNDRV_PCM_HW_PARAM_FIRST_MASK + 1;
    for (unsigned i = 0; i < nm; i++)
        for (unsigned b = 0; b < sizeof p.masks[i].bits / sizeof p.masks[i].bits[0]; b++)
            p.masks[i].bits[b] = ~0u;
    unsigned ni = SNDRV_PCM_HW_PARAM_LAST_INTERVAL - SNDRV_PCM_HW_PARAM_FIRST_INTERVAL + 1;
    for (unsigned i = 0; i < ni; i++) { p.intervals[i].min = 0; p.intervals[i].max = ~0u; }
    p.flags = 0;
    /* 坑②：mask 先清零再单点（pmask 只 OR）：全 1 的 access 会被内核 choose 成
     * MMAP_INTERLEAVED → write() 恒 EINVAL（本机 RW_INTERLEAVED 可用，须显式约束）。 */
    struct snd_mask *am = &p.masks[SNDRV_PCM_HW_PARAM_ACCESS - SNDRV_PCM_HW_PARAM_FIRST_MASK];
    memset(am, 0, sizeof *am); pmask(am, SNDRV_PCM_ACCESS_RW_INTERLEAVED);
    struct snd_mask *fm = &p.masks[SNDRV_PCM_HW_PARAM_FORMAT - SNDRV_PCM_HW_PARAM_FIRST_MASK];
    memset(fm, 0, sizeof *fm);
    pmask(fm, bits == 32 ? SNDRV_PCM_FORMAT_S32_LE : SNDRV_PCM_FORMAT_S16_LE);
    struct snd_mask *sm = &p.masks[SNDRV_PCM_HW_PARAM_SUBFORMAT - SNDRV_PCM_HW_PARAM_FIRST_MASK];
    memset(sm, 0, sizeof *sm); pmask(sm, SNDRV_PCM_SUBFORMAT_STD);
    pivset(&p.intervals[SNDRV_PCM_HW_PARAM_CHANNELS - SNDRV_PCM_HW_PARAM_FIRST_INTERVAL],
           (unsigned)ch);
    pivset(&p.intervals[SNDRV_PCM_HW_PARAM_RATE - SNDRV_PCM_HW_PARAM_FIRST_INTERVAL],
           (unsigned)rate);
    p.rmask = ~0u; p.info = 0; p.msbits = 0; p.rate_num = 0; p.rate_den = 0;
    if (ioctl(fd, SNDRV_PCM_IOCTL_HW_PARAMS, &p) != 0) {
        meow_log(MEOW_LOG_ERROR, "audio: alsa HW_PARAMS failed errno=%d rate=%d ch=%d",
                 errno, rate, ch);
        close(fd);
        return -1;
    }
    ioctl(fd, SNDRV_PCM_IOCTL_PREPARE, 0);
    meow_log(MEOW_LOG_INFO, "audio: alsa open ok rate=%d ch=%d bits=%d (direct debug)", rate, ch, bits);
    return fd;
}
#endif

/* 写 WAV 头（44 字节标准 PCM 布局：RIFF/WAVE/fmt(16)/data）。
 * fmt(16) = format(2) ch(2) sample_rate(4) byte_rate(4) block_align(2) bits(2)。
 * §19：bits 16/32 均合法（32=flac >16bit 的 S32 满幅样本）。 */
static void file_write_header(int fd, int rate, int ch, int bits, uint32_t data_len)
{
    unsigned char h[44];
    memset(h, 0, sizeof h);
    memcpy(h+0, "RIFF", 4);
    uint32_t le = 36 + data_len; memcpy(h+4, &le, 4);
    memcpy(h+8,  "WAVE", 4);
    memcpy(h+12, "fmt ", 4);
    le = 16; memcpy(h+16, &le, 4);
    uint16_t s16 = 1; memcpy(h+20, &s16, 2);            /* PCM */
    s16 = (uint16_t)ch; memcpy(h+22, &s16, 2);
    le = (uint32_t)rate;                 memcpy(h+24, &le, 4);   /* sample rate */
    le = (uint32_t)(rate * ch * bits / 8); memcpy(h+28, &le, 4); /* byte rate */
    s16 = (uint16_t)(ch * bits / 8);   memcpy(h+32, &s16, 2);    /* block align */
    s16 = (uint16_t)bits;              memcpy(h+34, &s16, 2);    /* bits/sample */
    memcpy(h+36, "data", 4);
    le = data_len; memcpy(h+40, &le, 4);
    if (write(fd, h, 44) != 44) { /* 忽略 */ }
}

static int file_open(int rate, int ch, int bits)
{
    int fd = open(g_path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
    if (fd < 0) {           /* 无路可写 → null */
        meow_log(MEOW_LOG_WARN, "audio: file open %s failed errno=%d -> null sink", g_path, errno);
        g_sink = SINK_NULL; g_fd = -1;
        return 0;
    }
    file_write_header(fd, rate, ch, bits, 0);
    g_sink = SINK_FILE;
    g_fd = fd;
    meow_log(MEOW_LOG_INFO, "audio: file sink %s rate=%d ch=%d bits=%d", g_path, rate, ch, bits);
    return 0;
}

/* ============================================================ */
/* 任务1：开播前把「系统当前音量」同步下发到 audiod                */
/* ============================================================ */
/* 背景（用户实测 2026-09-02）：未开始播放时音量不是系统设定值；按一下音量键才跳到设定值。
 * 根因= ncm 启动并打开 audiod/DAC 时，没有把系统当前音量下发到 audiod（meow_audiod 只在
 * MSG_AUDIO_VOLUME 收到时才写 DAC，流开/重配上不主动应用 settings 音量），导致 DAC 停在
 * 默认/上次残留音量；用户按音量键时 launcher/watchdog 那条音量链才更新并下发到 audiod。
 * 修法= SINK_AUDIOD open 成功后读 settings.conf 的 audio.volume，经 MSG_AUDIO_VOLUME 下发
 * （audiod 写 DAC numid=1/2 + 持久化 settings，同源同键）。语意：CS43198 寄存器=衰减量
 * （0 最响/255 静音），audiod dac_vol_set 负责反转与真静音（写 255），本处只传 pct。
 * 宿主验证：fake audiod socket 收帧断言 pct==系统设定（bench/vol_sync_sim.c）。 */

#define NCM_SETTINGS_CONF   "/usr/data/meow/settings.conf"   /* 与 audiod SETTINGS_CONF 同源 */
#define NCM_AUDIO_SOCK_DEF  "/usr/data/meow_audio.sock"      /* 与 audiod / SDK 客户端同缺省 */
#define NCM_VOL_DEFAULT     60                               /* 与 audiod VOL_DEFAULT/SDK 缺省一致 */
#define NCM_VOL_MAX         100

static const char *settings_conf_path(void)
{
    const char *e = getenv("MEOW_SETTINGS_FILE");   /* 宿主单测指向临时文件；设备缺省系统 conf */
    return (e && e[0]) ? e : NCM_SETTINGS_CONF;
}

/* 读 settings.conf 的 audio.volume（扁平 "key = value"；兼容无空格/多空格）。
 * 与 launcher meow_settings / SDK meow_ui_vol_read 同款解析。缺省 60；夹到 [0,100]。 */
static int settings_read_volume(void)
{
    static const char key[] = "audio.volume";
    const int kl = (int)sizeof key - 1;
    FILE *f = fopen(settings_conf_path(), "r");
    int vol = NCM_VOL_DEFAULT;
    if (!f) return vol;
    char line[160];
    while (fgets(line, sizeof line, f)) {
        char *eq = strchr(line, '=');
        if (!eq) continue;                                      /* 非 key=value 行跳过 */
        char *k = line;
        while (*k == ' ' || *k == '\t') k++;                    /* key 左去空白 */
        int n = (int)(eq - k);
        while (n > 0 && (k[n - 1] == ' ' || k[n - 1] == '\t')) n--;   /* key 右去空白 */
        if (n != kl || strncmp(k, key, (size_t)kl) != 0) continue;    /* 精确匹配 */
        char *v = eq + 1;
        while (*v == ' ' || *v == '\t') v++;                    /* value 左去空白 */
        int x = atoi(v);
        vol = (x < 0) ? 0 : (x > NCM_VOL_MAX ? NCM_VOL_MAX : x);
        break;
    }
    fclose(f);
    return vol;
}

/* 把 pct(0-100) 下发到 audiod。独立连接（SDK 客户端连接私有不可复用）；MSG_AUDIO_VOLUME
 * 不要求开流，audiod 侧写 DAC+持久化后 ACK（meow_audiod.c MSG_AUDIO_VOLUME）。失败仅日志，
 * 不影响播放本身（音量是次要正确性，非播放成败）。
 *
 * §2026-09-02 连接风暴根因：audiod_sync_volume 每次 audio_out_open 都新建一条 AF_UNIX
 * 短连接（socket→connect→write→close）。边下边播/切歌/seek 反复 open/close 时，audiod 端表现为
 * 「同一 fd=N 被反复 accept」（真机 1489 次 "io: client connected (fd=4)"）。音量值实际只在
 * 用户按音量键时变化，且 audiod 收到已持久化（settings_set_volume），无需每次 open 重发——
 * 修法：每进程首次 open 同步一次；此后仅当 settings 音量**变化**才重发（同一连接数坍缩为
 * O(1)，风暴消除）。失败不记 status（下次 open 仍会尝试，幂等）。 */
static void audiod_sync_volume(int pct)
{
    const char *sp = getenv("MEOW_AUDIO_SOCK");
    if (!sp || !sp[0]) sp = NCM_AUDIO_SOCK_DEF;
    int fd = socket(AF_UNIX, SOCK_STREAM, 0);
    if (fd < 0) return;
    struct sockaddr_un a;
    memset(&a, 0, sizeof a);
    a.sun_family = AF_UNIX;
    strncpy(a.sun_path, sp, sizeof a.sun_path - 1);
    if (connect(fd, (struct sockaddr *)&a, sizeof a) < 0) { close(fd); return; }

    uint8_t frame[MEOW_IPC_HDR_LEN + sizeof(int32_t)];
    uint32_t magic = MEOW_IPC_MAGIC, len = sizeof(int32_t), req = 1;
    uint16_t ver = MEOW_IPC_VERSION, type = MSG_AUDIO_VOLUME;
    memcpy(frame + 0,  &magic, 4);
    memcpy(frame + 4,  &ver,   2);
    memcpy(frame + 6,  &type,  2);
    memcpy(frame + 8,  &req,   4);
    memcpy(frame + 12, &len,   4);
    int32_t v32 = (int32_t)pct;
    memcpy(frame + 16, &v32, sizeof v32);
    if (write(fd, frame, sizeof frame) != (ssize_t)sizeof frame)
        meow_log(MEOW_LOG_WARN, "audio: sync volume write failed pct=%d", pct);
    close(fd);
}

/* 会话身份 = audiod 流 sid（g_sid）：切歌/新建音频会话 = 每次 audio_out_open 都向 audiod 开一条
 * 新流、audiod 分配新 sid（单调不重用）。此前用进程级 g_vol_synced「首次同步一次」——切歌（新会话）
 * 时音量不再被重发到 audiod，DAC 落在会话建立/重配后的默认/上次残留值（衰减量 0=最响），造成
 * 「切歌音量骤增，按一下音量键才回落到设定值」（用户真机 2026-09-05）。audiod 只在 reconfigure
 * 且参数变化时才 re-apply 音量（_audio_mark_reconfig_needed 同参数跳过），本会话重发是权威兜底。
 * 修法：**每会话首同步一次**——新 sid（新会话）必重发一次当前音量；同会话内仅值变才重发。
 * 每会话恰 1 条短连接，不回到「每次 open 都建连」的 fd 风暴（§2026-09-02 根因，vol_sync_sim 60 次
 * 同值→1 连接）。音量值取自 settings.conf（audiod 权威同源同键），反转/真静音(255) 由 audiod
 * dac_vol_set 负责，本层只传 pct(0-100)。 */
static int g_vol_synced_sid = -1;   /* 上次音量同步针对的 audiod 流 sid；-1=从未（必发） */
static int g_vol_last       = -1;

int audio_out_sync_volume(void)
{
    int pct = settings_read_volume();
    if (g_vol_synced_sid == g_sid && pct == g_vol_last) return 0;   /* 本会话已同步且值未变：零新建连接 */
    g_vol_synced_sid = g_sid;
    g_vol_last       = pct;
    audiod_sync_volume(pct);
    meow_log(MEOW_LOG_INFO, "audio: sync volume -> audiod pct=%d (settings %s, sid=%d)",
             pct, settings_conf_path(), g_sid);
    return 0;
}

int audio_out_open(int sample_rate, int channels, int bits)
{
    g_rate = sample_rate; g_ch = channels; g_bits = bits;
    g_wr_frames = 0; g_wr_errs = 0;
    const char *env = getenv("NCM_AUDIO_SINK");
    g_path = getenv("NCM_AUDIO_OUT");
    if (!g_path || !g_path[0]) g_path = NCM_DEFAULT_OUT;

    /* 显式 null（测解码 RT） */
    if (env && strcmp(env, "null") == 0) {
        g_sink = SINK_NULL; g_fd = -1;
        meow_log(MEOW_LOG_INFO, "audio: null sink rate=%d ch=%d", sample_rate, channels);
        return 0;
    }
    /* 显式 file（宿主/回归） */
    if (env && strcmp(env, "file") == 0)
        return file_open(sample_rate, channels, bits);

    /* 调试保底：ALSA 直开（仅显式指定；修法见文件头两大坑注释） */
    const char *de = getenv("MEOW_AUDIO_DIRECT");
    int want_alsa = (env && strcmp(env, "alsa") == 0) || (de && de[0] == '1');
    if (want_alsa) {
#ifdef NCM_HAVE_ALSA
        int fd = alsa_open(sample_rate, channels, bits);
        if (fd >= 0) { g_sink = SINK_ALSADEV; g_fd = fd; return 0; }
        meow_log(MEOW_LOG_ERROR, "audio: alsa direct open failed");
        return -1;
#else
        meow_log(MEOW_LOG_ERROR, "audio: alsa sink requested but no ALSA on this build");
        return -1;
#endif
    }

    /* 默认：SINK_AUDIOD（meow_audiod 独占服务）。§19：bits 16→S16 / 32→S32
     * （flac >16bit 由 dr_flac 出 S32 满幅；格式归一/DAC 原生率跟随在 audiod 侧）。 */
    int fmt;
    if (bits == 16)      fmt = AUDIO_FMT_S16;
    else if (bits == 32) fmt = AUDIO_FMT_S32;
    else {
        meow_log(MEOW_LOG_ERROR, "audio: audiod open: bits=%d unsupported (16/32)", bits);
        return -1;
    }
    int sid = meow_audio_open(sample_rate, channels, fmt);
    if (sid < 0) {
        meow_log(MEOW_LOG_ERROR, "audio: audiod open failed rc=%d rate=%d ch=%d (audiod 不在?)",
                 sid, sample_rate, channels);
        return -1;
    }
    g_sink = SINK_AUDIOD;
    g_sid = sid;
    /* 授权参数（grant_*）落日志：无声排查关键资产 */
    meow_audio_state st;
    if (meow_audio_query(&st) == 0)
        meow_log(MEOW_LOG_INFO,
                 "audio: audiod open ok sid=%d req=%dHz/%dch/%dbit grant=%uHz/%uch/fmt=%u underrun=%u",
                 sid, sample_rate, channels, bits, st.rate, st.ch, st.fmt, st.underrun);
    else
        meow_log(MEOW_LOG_INFO, "audio: audiod open ok sid=%d req=%dHz/%dch/%dbit",
                 sid, sample_rate, channels, bits);
    /* 任务1：开播/打开音频会话时把系统当前音量同步下发到 audiod（DAC 停在默认/上次残留音量的根治）。
     * 幂等（同值重写无害）；失败不阻断播放。 */
    audio_out_sync_volume();
    return 0;
}

int audio_out_write(const void *samples, int frames)
{
    if (g_app_quit) return -1;
    if (g_sink == SINK_NULL || g_sink < 0) return frames;
    if (g_sink == SINK_AUDIOD) {
        int w = meow_audio_write(samples, frames);
        if (w != frames) {
            g_wr_errs++;
            if (g_wr_errs == 1 || (g_wr_errs % 100) == 0)
                meow_log(MEOW_LOG_ERROR, "audio: audiod write failed rc=%d frames=%d (errs=%d)",
                         w, frames, g_wr_errs);
            return -1;
        }
        g_wr_frames += (uint64_t)frames;
        return frames;
    }
    size_t n = (size_t)frames * (size_t)g_ch * (size_t)(g_bits / 8);
    if (g_sink == SINK_ALSADEV) {
        /* 阻塞尽力写满 - EINTR/EAGAIN 重试；错误返回 */
        const unsigned char *p = (const unsigned char *)samples;
        size_t off = 0;
        while (off < n) {
            ssize_t w = write(g_fd, p + off, n - off);
            if (w > 0) { off += (size_t)w; continue; }
            if (w < 0 && (errno == EINTR || errno == EAGAIN)) continue;
            meow_log(MEOW_LOG_ERROR, "audio: alsa write failed errno=%d", errno);
            return -1;
        }
        g_wr_frames += (uint64_t)frames;
        return frames;
    }
    if (g_sink == SINK_FILE) {
        if (write(g_fd, samples, n) != (ssize_t)n) return -1;
        g_wr_frames += (uint64_t)frames;
        return frames;
    }
    return frames;
}

/* 暂停(1)/恢复(0) audiod 流（停 PCM 时钟但不丢流）。仅 AUDIOD 后端有效，其余后端恒 0。
 * 恢复时若流已死（被抢占/audiod 断链）→ 自动重开（解码位置不变，仅重建输出流）。 */
int audio_out_pause(int paused)
{
    if (g_sink != SINK_AUDIOD || g_sid <= 0) return 0;
    int rc = meow_audio_pause(g_sid, paused);
    if (rc >= 0) {
        meow_log(MEOW_LOG_INFO, "audio: audiod %s sid=%d ok", paused ? "pause" : "resume", g_sid);
        return 0;
    }
    if (paused) {       /* 暂停失败（流多半已死）：记日志即可，恢复时会走重开 */
        meow_log(MEOW_LOG_WARN, "audio: audiod pause sid=%d rc=%d (stream dead?)", g_sid, rc);
        return 0;
    }
    /* 恢复失败 = 流已死 → 重开（格式按本次 open 的 bits 还原：16→S16 / 32→S32） */
    meow_log(MEOW_LOG_WARN, "audio: audiod resume sid=%d rc=%d -> reopen", g_sid, rc);
    meow_audio_close(g_sid);
    g_sid = 0;
    int sid = meow_audio_open(g_rate, g_ch, g_bits == 32 ? AUDIO_FMT_S32 : AUDIO_FMT_S16);
    if (sid < 0) {
        meow_log(MEOW_LOG_ERROR, "audio: audiod reopen failed rc=%d rate=%d ch=%d", sid, g_rate, g_ch);
        return -1;
    }
    g_sid = sid;
    meow_log(MEOW_LOG_INFO, "audio: audiod reopen ok sid=%d", sid);
    audio_out_sync_volume();   /* 新会话（新 sid）：音量权威兜底重发一次（DAC 复位后不残留默认响度） */
    return 0;
}

void audio_out_close(void)
{
    if (g_sink == SINK_AUDIOD) {
        if (g_sid > 0) {
            meow_audio_close(g_sid);
            meow_log(MEOW_LOG_INFO, "audio: audiod close sid=%d written_frames=%llu wr_errs=%d",
                     g_sid, (unsigned long long)g_wr_frames, g_wr_errs);
            g_sid = 0;
        }
        g_sink = -1;
        return;
    }
    if (g_sink == SINK_FILE && g_fd >= 0) {
        /* 回填：offset 4 = RIFF 总长-36；offset 40 = data 长度 */
        off_t end = lseek(g_fd, 0, SEEK_END);
        if (end > 44) {
            uint32_t data_len = (uint32_t)(end - 44);
            lseek(g_fd, 4, SEEK_SET);
            uint32_t le = 36 + data_len;
            if (write(g_fd, &le, 4) != 4) { }
            lseek(g_fd, 40, SEEK_SET);
            if (write(g_fd, &data_len, 4) != 4) { }
        }
    }
    if (g_fd >= 0) close(g_fd);
    g_fd = -1;
    g_sink = -1;
}