static int control(struct dec_audio *da, int cmd, void *arg)
{
    struct ad_mpg123_context *con = da->priv;

    switch (cmd) {
    case ADCTRL_RESET:
        mp_audio_set_null_data(&da->decoded);
        mpg123_close(con->handle);

        if (mpg123_open_feed(con->handle) != MPG123_OK) {
            MP_ERR(da, "mpg123 failed to reopen stream: %s\n",
                   mpg123_strerror(con->handle));
            return CONTROL_FALSE;
        }
        return CONTROL_TRUE;
    }
    return CONTROL_UNKNOWN;
}

static int hotplug_init(struct ao *ao)
{
    MP_DBG(ao, "Hotplug init\n");
    struct wasapi_state *state = ao->priv;
    state->log = ao->log;
    CoInitializeEx(NULL, COINIT_APARTMENTTHREADED);
    HRESULT hr = CoCreateInstance(&CLSID_MMDeviceEnumerator, NULL, CLSCTX_ALL,
                                  &IID_IMMDeviceEnumerator, (void **)&state->pEnumerator);
    EXIT_ON_ERROR(hr);
    hr = wasapi_change_init(ao, true);
    EXIT_ON_ERROR(hr);

    return 0;
    exit_label:
    MP_ERR(state, "Error setting up audio hotplug: %s\n", mp_HRESULT_to_str(hr));
    hotplug_uninit(ao);
    return -1;
}

static int recreate_audio_filters(struct MPContext *mpctx)
{
    struct ao_chain *ao_c = mpctx->ao_chain;
    assert(ao_c);

    if (!mp_output_chain_update_filters(ao_c->filter, mpctx->opts->af_settings))
        goto fail;

    update_speed_filters(mpctx);

    mp_notify(mpctx, MPV_EVENT_AUDIO_RECONFIG, NULL);

    return 0;

fail:
    MP_ERR(mpctx, "Audio filter initialized failed!\n");
    return -1;
}

static void hotplug_uninit(struct ao *ao)
{
    OSStatus err = noErr;
    for (int i = 0; i < MP_ARRAY_SIZE(hotplug_properties); i++) {
        AudioObjectPropertyAddress addr = {
            hotplug_properties[i],
            kAudioObjectPropertyScopeGlobal,
            kAudioObjectPropertyElementMaster
        };
        err = AudioObjectRemovePropertyListener(
            kAudioObjectSystemObject, &addr, hotplug_cb, (void *)ao);
        if (err != noErr) {
            char *c1 = fourcc_repr(hotplug_properties[i]);
            char *c2 = fourcc_repr(err);
            MP_ERR(ao, "failed to set device listener %s (%s)", c1, c2);
        }
    }
}

bool ca_init_chmap(struct ao *ao, AudioDeviceID device)
{
    struct mp_chmap_sel chmap_sel = {0};
    ca_retrieve_layouts(ao, &chmap_sel, device);

    if (!chmap_sel.num_chmaps)
        mp_chmap_sel_add_map(&chmap_sel, &(struct mp_chmap)MP_CHMAP_INIT_STEREO);

    mp_chmap_sel_add_map(&chmap_sel, &(struct mp_chmap)MP_CHMAP_INIT_MONO);

    if (!ao_chmap_sel_adjust(ao, &chmap_sel, &ao->channels)) {
        MP_ERR(ao, "could not select a suitable channel map among the "
                   "hardware supported ones. Make sure to configure your "
                   "output device correctly in 'Audio MIDI Setup.app'\n");
        return false;
    }
    return true;
}

static void update_framebuffer_from_bo(
    const struct MPGLContext *ctx, struct gbm_bo *bo)
{
    struct priv *p = ctx->priv;
    p->fb.bo = bo;
    p->fb.fd = p->kms->fd;
    p->fb.width = gbm_bo_get_width(bo);
    p->fb.height = gbm_bo_get_height(bo);
    int stride = gbm_bo_get_stride(bo);
    int handle = gbm_bo_get_handle(bo).u32;

    int ret = drmModeAddFB(p->kms->fd, p->fb.width, p->fb.height,
                       24, 32, stride, handle, &p->fb.id);
    if (ret) {
        MP_ERR(ctx->vo, "Failed to create framebuffer: %s\n", mp_strerror(errno));
    }
    gbm_bo_set_user_data(bo, &p->fb, framebuffer_destroy_callback);
}

static void get_and_update_icc_profile(struct gl_priv *p, int *events)
{
    if (gl_video_icc_auto_enabled(p->renderer)) {
        MP_VERBOSE(p, "Querying ICC profile...\n");
        bstr icc = bstr0(NULL);
        int r = mpgl_control(p->glctx, events, VOCTRL_GET_ICC_PROFILE, &icc);

        if (r != VO_NOTAVAIL) {
            if (r == VO_FALSE) {
                MP_WARN(p, "Could not retrieve an ICC profile.\n");
            } else if (r == VO_NOTIMPL) {
                MP_ERR(p, "icc-profile-auto not implemented on this platform.\n");
            }

            gl_video_set_icc_profile(p->renderer, icc);
        }
    }
}

// Iterate entries. The first call establishes the first entry. Returns false
// if no entry found, otherwise returns true and sets mpa->entry/entry_filename.
bool mp_archive_next_entry(struct mp_archive *mpa)
{
    mpa->entry = NULL;
    talloc_free(mpa->entry_filename);
    mpa->entry_filename = NULL;

    if (!mpa->arch)
        return false;

    locale_t oldlocale = uselocale(mpa->locale);
    bool success = false;

    while (!mp_cancel_test(mpa->primary_src->cancel)) {
        struct archive_entry *entry;
        int r = archive_read_next_header(mpa->arch, &entry);
        if (r == ARCHIVE_EOF)
            break;
        if (r < ARCHIVE_OK)
            MP_ERR(mpa, "%s\n", archive_error_string(mpa->arch));
        if (r < ARCHIVE_WARN) {
            MP_FATAL(mpa, "could not read archive entry\n");
            mp_archive_check_fatal(mpa, r);
            break;
        }
        if (archive_entry_filetype(entry) != AE_IFREG)
            continue;
        // Some archives may have no filenames, or libarchive won't return some.
        const char *fn = archive_entry_pathname(entry);
        char buf[64];
        if (!fn || bstr_validate_utf8(bstr0(fn)) < 0) {
            snprintf(buf, sizeof(buf), "mpv_unknown#%d", mpa->entry_num);
            fn = buf;
        }
        mpa->entry = entry;
        mpa->entry_filename = talloc_strdup(mpa, fn);
        mpa->entry_num += 1;
        success = true;
        break;
    }

    uselocale(oldlocale);

    return success;
}

static HRESULT get_device_delay(struct wasapi_state *state, double *delay_us) {
    UINT64 sample_count = atomic_load(&state->sample_count);
    UINT64 position, qpc_position;
    HRESULT hr;

    hr = IAudioClock_GetPosition(state->pAudioClock, &position, &qpc_position);
    // GetPosition succeeded, but the result may be
    // inaccurate due to the length of the call
    // http://msdn.microsoft.com/en-us/library/windows/desktop/dd370889%28v=vs.85%29.aspx
    if (hr == S_FALSE) {
        MP_VERBOSE(state, "Possibly inaccurate device position.\n");
        hr = S_OK;
    }
    EXIT_ON_ERROR(hr);

    // convert position to number of samples careful to avoid overflow
    UINT64 sample_position = uint64_scale(position,
                                          state->format.Format.nSamplesPerSec,
                                          state->clock_frequency);
    INT64 diff = sample_count - sample_position;
    *delay_us = diff * 1e6 / state->format.Format.nSamplesPerSec;

    // Correct for any delay in IAudioClock_GetPosition above.
    // This should normally be very small (<1 us), but just in case. . .
    LARGE_INTEGER qpc;
    QueryPerformanceCounter(&qpc);
    INT64 qpc_diff = av_rescale(qpc.QuadPart, 10000000, state->qpc_frequency.QuadPart)
                     - qpc_position;
    // ignore the above calculation if it yeilds more than 10 seconds (due to
    // possible overflow inside IAudioClock_GetPosition)
    if (qpc_diff < 10 * 10000000) {
        *delay_us -= qpc_diff / 10.0; // convert to us
    } else {
        MP_VERBOSE(state, "Insane qpc delay correction of %g seconds. "
                   "Ignoring it.\n", qpc_diff / 10000000.0);
    }

    MP_TRACE(state, "Device delay: %g us\n", *delay_us);

    return S_OK;
exit_label:
    MP_ERR(state, "Error getting device delay: %s\n", mp_HRESULT_to_str(hr));
    return hr;
}

// Return true if this was a readable directory.
static bool scan_dir(struct pl_parser *p, char *path,
                     struct stat *dir_stack, int num_dir_stack,
                     char ***files, int *num_files)
{
    if (strlen(path) >= 8192 || num_dir_stack == MAX_DIR_STACK)
        return false; // things like mount bind loops

    DIR *dp = opendir(path);
    if (!dp) {
        MP_ERR(p, "Could not read directory.\n");
        return false;
    }

    struct dirent *ep;
    while ((ep = readdir(dp))) {
        if (ep->d_name[0] == '.')
            continue;

        if (mp_cancel_test(p->s->cancel))
            break;

        char *file = mp_path_join(p, path, ep->d_name);

        struct stat st;
        if (stat(file, &st) == 0 && S_ISDIR(st.st_mode)) {
            for (int n = 0; n < num_dir_stack; n++) {
                if (same_st(&dir_stack[n], &st)) {
                    MP_VERBOSE(p, "Skip recursive entry: %s\n", file);
                    goto skip;
                }
            }

            dir_stack[num_dir_stack] = st;
            scan_dir(p, file, dir_stack, num_dir_stack + 1, files, num_files);
        } else {
            MP_TARRAY_APPEND(p, *files, *num_files, file);
        }

        skip: ;
    }

    closedir(dp);
    return true;
}

static void thread_feed(struct ao *ao)
{
    struct wasapi_state *state = ao->priv;
    HRESULT hr;

    UINT32 frame_count = state->bufferFrameCount;

    if (state->share_mode == AUDCLNT_SHAREMODE_SHARED) {
        UINT32 padding = 0;
        hr = IAudioClient_GetCurrentPadding(state->pAudioClient, &padding);
        EXIT_ON_ERROR(hr);

        frame_count -= padding;
        MP_TRACE(ao, "Frame to fill: %"PRIu32". Padding: %"PRIu32"\n", frame_count, padding);
    }
    double delay;
    hr = get_device_delay(state, &delay);
    EXIT_ON_ERROR(hr);

    BYTE *pData;
    hr = IAudioRenderClient_GetBuffer(state->pRenderClient,
                                      frame_count, &pData);
    EXIT_ON_ERROR(hr);

    BYTE *data[1] = {pData};

    ao_read_data(ao, (void**)data, frame_count, (int64_t) (
                     mp_time_us() + delay * 1e6 +
                     frame_count * 1e6 / state->format.Format.nSamplesPerSec));

    hr = IAudioRenderClient_ReleaseBuffer(state->pRenderClient,
                                          frame_count, 0);
    EXIT_ON_ERROR(hr);

    atomic_fetch_add(&state->sample_count, frame_count);

    return;
exit_label:
    MP_ERR(state, "Error feeding audio: %s\n", mp_HRESULT_to_str(hr));
    MP_VERBOSE(ao, "Requesting ao reload\n");
    ao_request_reload(ao);
    return;
}

bool video_init_best_codec(struct dec_video *d_video, char* video_decoders)
{
    assert(!d_video->vd_driver);
    video_reset_decoding(d_video);
    d_video->has_broken_packet_pts = -10; // needs 10 packets to reach decision

    struct mp_decoder_entry *decoder = NULL;
    struct mp_decoder_list *list =
        mp_select_video_decoders(d_video->header->codec, video_decoders);

    mp_print_decoders(d_video->log, MSGL_V, "Codec list:", list);

    for (int n = 0; n < list->num_entries; n++) {
        struct mp_decoder_entry *sel = &list->entries[n];
        const struct vd_functions *driver = find_driver(sel->family);
        if (!driver)
            continue;
        MP_VERBOSE(d_video, "Opening video decoder %s:%s\n",
                   sel->family, sel->decoder);
        d_video->vd_driver = driver;
        if (init_video_codec(d_video, sel->decoder)) {
            decoder = sel;
            break;
        }
        d_video->vd_driver = NULL;
        MP_WARN(d_video, "Video decoder init failed for "
                "%s:%s\n", sel->family, sel->decoder);
    }

    if (d_video->vd_driver) {
        d_video->decoder_desc =
            talloc_asprintf(d_video, "%s [%s:%s]", decoder->desc, decoder->family,
                            decoder->decoder);
        MP_INFO(d_video, "Selected video codec: %s\n",
                d_video->decoder_desc);
    } else {
        MP_ERR(d_video, "Failed to initialize a video decoder for codec '%s'.\n",
               d_video->header->codec ? d_video->header->codec : "<unknown>");
    }

    talloc_free(list);
    return !!d_video->vd_driver;
}

static int filter_ext(struct vf_instance *vf, struct mp_image *mpi)
{
    VdpStatus vdp_st;
    struct vf_priv_s *p = vf->priv;
    struct mp_vdpau_ctx *ctx = p->ctx;
    struct vdp_functions *vdp = &ctx->vdp;

    if (!mpi) {
        return 0;
    }

    // Pass-through anything that's not been decoded by VDPAU
    if (mpi->imgfmt != IMGFMT_VDPAU) {
        vf_add_output_frame(vf, mpi);
        return 0;
    }

    if (mp_vdpau_mixed_frame_get(mpi)) {
        MP_ERR(vf, "Can't apply vdpaurb filter after vdpaupp filter.\n");
        mp_image_unrefp(&mpi);
        return -1;
    }

    struct mp_image *out = vf_alloc_out_image(vf);
    if (!out) {
        mp_image_unrefp(&mpi);
        return -1;
    }
    mp_image_copy_attributes(out, mpi);

    VdpVideoSurface surface = (uintptr_t)mpi->planes[3];
    assert(surface > 0);

    vdp_st = vdp->video_surface_get_bits_y_cb_cr(surface,
                                                 VDP_YCBCR_FORMAT_NV12,
                                                 (void * const *)out->planes,
                                                 out->stride);
    CHECK_VDP_WARNING(vf, "Error when calling vdp_output_surface_get_bits_y_cb_cr");

    vf_add_output_frame(vf, out);
    mp_image_unrefp(&mpi);
    return 0;
}

int audio_init_best_codec(struct dec_audio *d_audio, char *audio_decoders)
{
    assert(!d_audio->ad_driver);
    audio_reset_decoding(d_audio);

    struct mp_decoder_entry *decoder = NULL;
    struct mp_decoder_list *list =
        audio_select_decoders(d_audio->header->codec, audio_decoders);

    mp_print_decoders(d_audio->log, MSGL_V, "Codec list:", list);

    for (int n = 0; n < list->num_entries; n++) {
        struct mp_decoder_entry *sel = &list->entries[n];
        const struct ad_functions *driver = find_driver(sel->family);
        if (!driver)
            continue;
        MP_VERBOSE(d_audio, "Opening audio decoder %s:%s\n",
                   sel->family, sel->decoder);
        d_audio->ad_driver = driver;
        if (init_audio_codec(d_audio, sel->decoder)) {
            decoder = sel;
            break;
        }
        MP_WARN(d_audio, "Audio decoder init failed for "
                "%s:%s\n", sel->family, sel->decoder);
    }

    if (d_audio->ad_driver) {
        d_audio->decoder_desc =
            talloc_asprintf(d_audio, "%s [%s:%s]", decoder->desc, decoder->family,
                            decoder->decoder);
        MP_VERBOSE(d_audio, "Selected audio codec: %s\n", d_audio->decoder_desc);
        MP_VERBOSE(d_audio, "AUDIO: %d Hz, %d ch, %s\n",
                   d_audio->decoded.rate, d_audio->decoded.channels.num,
                   af_fmt_to_str(d_audio->decoded.format));
    } else {
        MP_ERR(d_audio, "Failed to initialize an audio decoder for codec '%s'.\n",
               d_audio->header->codec ? d_audio->header->codec : "<unknown>");
    }

    talloc_free(list);
    return !!d_audio->ad_driver;
}

// Reconfigure the filter chain according to decoder output.
// probe_only: don't force fallback to software when doing hw decoding, and
//             the filter chain couldn't be configured
static void filter_reconfig(struct MPContext *mpctx,
                            bool probe_only)
{
    struct dec_video *d_video = mpctx->d_video;

    struct mp_image_params params = d_video->decoder_output;

    set_allowed_vo_formats(d_video->vfilter, mpctx->video_out);

    if (video_reconfig_filters(d_video, &params) < 0) {
        // Most video filters don't work with hardware decoding, so this
        // might be the reason why filter reconfig failed.
        if (!probe_only &&
            video_vd_control(d_video, VDCTRL_FORCE_HWDEC_FALLBACK, NULL) == CONTROL_OK)
        {
            // Fallback active; decoder will return software format next
            // time. Don't abort video decoding.
            d_video->vfilter->initialized = 0;
            mp_image_unrefp(&d_video->waiting_decoded_mpi);
            d_video->decoder_output = (struct mp_image_params){0};
            MP_VERBOSE(mpctx, "hwdec falback due to filters.\n");
        }
        return;
    }

    if (d_video->vfilter->initialized < 1)
        return;

    if (params.rotate && (params.rotate % 90 == 0)) {
        if (!(mpctx->video_out->driver->caps & VO_CAP_ROTATE90)) {
            // Try to insert a rotation filter.
            char deg[10];
            snprintf(deg, sizeof(deg), "%d", params.rotate);
            char *args[] = {"angle", deg, NULL, NULL};
            if (try_filter(mpctx, params, "rotate", "autorotate", args) >= 0) {
                params.rotate = 0;
            } else {
                MP_ERR(mpctx, "Can't insert rotation filter.\n");
            }
        }
    }
}

int ai_alsa_init(audio_in_t *ai)
{
    int err;

    err = snd_pcm_open(&ai->alsa.handle, ai->alsa.device, SND_PCM_STREAM_CAPTURE, 0);
    if (err < 0) {
        MP_ERR(ai, "Error opening audio: %s\n", snd_strerror(err));
        return -1;
    }

    err = snd_output_stdio_attach(&ai->alsa.log, stderr, 0);

    if (err < 0) {
        return -1;
    }

    err = ai_alsa_setup(ai);

    return err;
}

int dvb_step_channel(stream_t *stream, int dir)
{
    int new_current;
    dvb_channels_list *list;
    dvb_priv_t *priv = stream->priv;
    dvb_state_t* state = priv->state;

    MP_VERBOSE(stream, "DVB_STEP_CHANNEL dir %d\n", dir);

    list = state->list;
    if (list == NULL) {
        MP_ERR(stream, "dvb_step_channel: NULL list_ptr, quit\n");
        return 0;
    }

    new_current = (list->NUM_CHANNELS + list->current +
                  (dir >= 0 ? 1 : -1)) % list->NUM_CHANNELS;

    return dvb_set_channel(stream, state->card, new_current);
}

static void write_packet(struct ao *ao, AVPacket *packet)
{
    // TODO: Can we unify this with the equivalent video code path?
    struct priv *ac = ao->priv;

    packet->stream_index = ac->stream->index;
    if (packet->pts != AV_NOPTS_VALUE) {
        packet->pts = av_rescale_q(packet->pts,
                                   ac->codec->time_base,
                                   ac->stream->time_base);
    } else {
        // Do we need this at all? Better be safe than sorry...
        MP_WARN(ao, "encoder lost pts, why?\n");
        if (ac->savepts != MP_NOPTS_VALUE) {
            packet->pts = av_rescale_q(ac->savepts,
                                       ac->codec->time_base,
                                       ac->stream->time_base);
        }
    }
    if (packet->dts != AV_NOPTS_VALUE) {
        packet->dts = av_rescale_q(packet->dts,
                                   ac->codec->time_base,
                                   ac->stream->time_base);
    }
    if (packet->duration > 0) {
        packet->duration = av_rescale_q(packet->duration,
                                        ac->codec->time_base,
                                        ac->stream->time_base);
    }

    ac->savepts = AV_NOPTS_VALUE;

    if (encode_lavc_write_frame(ao->encode_lavc_ctx,
                                ac->stream, packet) < 0) {
        MP_ERR(ao, "error writing at %d %d/%d\n",
               (int) packet->pts,
               ac->stream->time_base.num,
               ac->stream->time_base.den);
        return;
    }
}

/**
 * @brief Copy Constructor for stationlist
 *
 * @see parse_setup_stationlist
 */
static int
copycreate_stationlist (struct pvr_t *pvr, stationlist_t *stationlist, int num)
{
  int i;

  if (chantab < 0 || !stationlist)
    return -1;

  num = FFMAX (num, chanlists[chantab].count);

  free (stationlist->list);
  stationlist->list = NULL;

  stationlist->total = 0;
  stationlist->enabled = 0;
  stationlist->used = 0;
  stationlist->list = calloc (num, sizeof (station_elem_t));

  if (!stationlist->list)
  {
    MP_ERR(pvr, "%s No memory allocated for station list, giving up\n",
            LOG_LEVEL_V4L2);
    return -1;
  }

  /* transport the channel list data to our extented struct */
  stationlist->total = num;
  BUFSTRCPY(stationlist->name, chanlists[chantab].name);

  for (i = 0; i < chanlists[chantab].count; i++)
  {
    stationlist->list[i].station[0]= '\0'; /* no station name yet */
    BUFSTRCPY(stationlist->list[i].name, chanlists[chantab].list[i].name);
    stationlist->list[i].freq = chanlists[chantab].list[i].freq;
    stationlist->list[i].enabled = 1; /* default enabled */
    stationlist->enabled++;
    stationlist->used++;
  }

  return 0;
}

static bool create_dc(struct MPGLContext *ctx, int flags)
{
    struct w32_context *w32_ctx = ctx->priv;
    HWND win = vo_w32_hwnd(ctx->vo);

    if (w32_ctx->hdc)
        return true;

    HDC hdc = GetDC(win);
    if (!hdc)
        return false;

    PIXELFORMATDESCRIPTOR pfd;
    memset(&pfd, 0, sizeof pfd);
    pfd.nSize = sizeof pfd;
    pfd.nVersion = 1;
    pfd.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER;

    pfd.iPixelType = PFD_TYPE_RGBA;
    pfd.cColorBits = 24;
    pfd.iLayerType = PFD_MAIN_PLANE;
    int pf = ChoosePixelFormat(hdc, &pfd);

    if (!pf) {
        MP_ERR(ctx->vo, "unable to select a valid pixel format!\n");
        ReleaseDC(win, hdc);
        return false;
    }

    SetPixelFormat(hdc, pf, &pfd);

    int pfmt = GetPixelFormat(hdc);
    if (DescribePixelFormat(hdc, pfmt, sizeof(PIXELFORMATDESCRIPTOR), &pfd)) {
        ctx->depth_r = pfd.cRedBits;
        ctx->depth_g = pfd.cGreenBits;
        ctx->depth_b = pfd.cBlueBits;
    }

    w32_ctx->hdc = hdc;
    return true;
}