/*

 * PCM audio output driver

 *

 * Original author: Atmosfear

 *

 * This file is part of mpv.

 *

 * mpv is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * mpv is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with mpv.  If not, see <http://www.gnu.org/licenses/>.

 */

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <libavutil/common.h>

#include "mpv_talloc.h"

#include "options/m_option.h"

#include "options/path.h"

#include "audio/format.h"

#include "ao.h"

#include "internal.h"

#include "common/msg.h"

#include "osdep/endian.h"

#ifdef _WIN32

// for GetFileType to detect pipes

#include <windows.h>

#include <io.h>

#endif

struct priv {

    char *outputfilename;

    bool waveheader;

    bool append;

    uint64_t data_length;

    FILE *fp;

};

#define WAV_ID_RIFF 0x46464952 /* "RIFF" */

#define WAV_ID_WAVE 0x45564157 /* "WAVE" */

#define WAV_ID_FMT  0x20746d66 /* "fmt " */

#define WAV_ID_DATA 0x61746164 /* "data" */

#define WAV_ID_PCM  0x0001

#define WAV_ID_FLOAT_PCM  0x0003

#define WAV_ID_FORMAT_EXTENSIBLE 0xfffe

static void fput16le(uint16_t val, FILE *fp)

{

    uint8_t bytes[2] = {val, val >> 8};

    fwrite(bytes, 1, 2, fp);

}

static void fput32le(uint32_t val, FILE *fp)

{

    uint8_t bytes[4] = {val, val >> 8, val >> 16, val >> 24};

    fwrite(bytes, 1, 4, fp);

}

static void write_wave_header(struct ao *ao, FILE *fp, uint64_t data_length)

{

    uint16_t fmt = ao->format == AF_FORMAT_FLOAT ? WAV_ID_FLOAT_PCM : WAV_ID_PCM;

    int bits = af_fmt_to_bytes(ao->format) * 8;

    // Master RIFF chunk

    fput32le(WAV_ID_RIFF, fp);

    // RIFF chunk size: 'WAVE' + 'fmt ' + 4 + 40 +

    // data chunk hdr (8) + data length

    fput32le(12 + 40 + 8 + data_length, fp);

    fput32le(WAV_ID_WAVE, fp);

    // Format chunk

    fput32le(WAV_ID_FMT, fp);

    fput32le(40, fp);

    fput16le(WAV_ID_FORMAT_EXTENSIBLE, fp);

    fput16le(ao->channels.num, fp);

    fput32le(ao->samplerate, fp);

    fput32le(MPCLAMP(ao->bps, 0, UINT32_MAX), fp);

    fput16le(ao->channels.num * (bits / 8), fp);

    fput16le(bits, fp);

    // Extension chunk

    fput16le(22, fp);

    fput16le(bits, fp);

    fput32le(mp_chmap_to_waveext(&ao->channels), fp);

    // 2 bytes format + 14 bytes guid

    fput32le(fmt, fp);

    fput32le(0x00100000, fp);

    fput32le(0xAA000080, fp);

    fput32le(0x719B3800, fp);

    // Data chunk

    fput32le(WAV_ID_DATA, fp);

    fput32le(data_length, fp);

}

static int init(struct ao *ao)

{

    struct priv *priv = ao->priv;

    char *outputfilename = mp_get_user_path(priv, ao->global, priv->outputfilename);

    if (!outputfilename) {

        outputfilename = talloc_strdup(priv, priv->waveheader ? "audiodump.wav"

                                                              : "audiodump.pcm");

    }

    ao->format = af_fmt_from_planar(ao->format);

    if (priv->waveheader) {

        // WAV files must have one of the following formats

        // And they don't work in big endian; fixing it would be simple, but

        // nobody cares.

        if (BYTE_ORDER == BIG_ENDIAN) {

            MP_FATAL(ao, "Not supported on big endian.\n");

            return -1;

        }

        switch (ao->format) {

        case AF_FORMAT_U8:

        case AF_FORMAT_S16:

        case AF_FORMAT_S32:

        case AF_FORMAT_FLOAT:

             break;

        default:

            if (!af_fmt_is_spdif(ao->format))

                ao->format = AF_FORMAT_S16;

            break;

        }

    }

    struct mp_chmap_sel sel = {0};

    mp_chmap_sel_add_waveext(&sel);

    if (!ao_chmap_sel_adjust(ao, &sel, &ao->channels))

        return -1;

    ao->bps = ao->channels.num * (int64_t)ao->samplerate * af_fmt_to_bytes(ao->format);

    MP_INFO(ao, "File: %s (%s)\nPCM: Samplerate: %d Hz Channels: %d Format: %s\n",

            outputfilename,

            priv->waveheader ? "WAVE" : "RAW PCM", ao->samplerate,

            ao->channels.num, af_fmt_to_str(ao->format));

    priv->fp = fopen(outputfilename, priv->append ? "ab" : "wb");

    if (!priv->fp) {

        MP_ERR(ao, "Failed to open %s for writing!\n", outputfilename);

        return -1;

    }

    if (priv->waveheader)  // Reserve space for wave header

        write_wave_header(ao, priv->fp, 0x7ffff000);

    ao->untimed = true;

    ao->device_buffer = 1 << 16;

    return 0;

}

// close audio device

static void uninit(struct ao *ao)

{

    struct priv *priv = ao->priv;

    if (priv->waveheader) {    // Rewrite wave header

        bool broken_seek = false;

#ifdef _WIN32

        // Windows, in its usual idiocy "emulates" seeks on pipes so it always

        // looks like they work. So we have to detect them brute-force.

        broken_seek = FILE_TYPE_DISK !=

            GetFileType((HANDLE)_get_osfhandle(_fileno(priv->fp)));

#endif

        if (broken_seek || fseek(priv->fp, 0, SEEK_SET) != 0)

            MP_ERR(ao, "Could not seek to start, WAV size headers not updated!\n");

        else {

            if (priv->data_length > 0xfffff000) {

                MP_ERR(ao, "File larger than allowed for "

                       "WAV files, may play truncated!\n");

                priv->data_length = 0xfffff000;

            }

            write_wave_header(ao, priv->fp, priv->data_length);

        }

    }

    fclose(priv->fp);

}

static bool audio_write(struct ao *ao, void **data, int samples)

{

    struct priv *priv = ao->priv;

    int len = samples * ao->sstride;

    fwrite(data[0], len, 1, priv->fp);

    priv->data_length += len;

    return true;

}

static void get_state(struct ao *ao, struct mp_pcm_state *state)

{

    state->free_samples = ao->device_buffer;

    state->queued_samples = 0;

    state->delay = 0;

}

static bool set_pause(struct ao *ao, bool paused)

{

    return true; // signal support so common code doesn't write silence

}

static void start(struct ao *ao)

{

    // we use data immediately

}

static void reset(struct ao *ao)

{

}

#define OPT_BASE_STRUCT struct priv

const struct ao_driver audio_out_pcm = {

    .description = "RAW PCM/WAVE file writer audio output",

    .name      = "pcm",

    .init      = init,

    .uninit    = uninit,

    .get_state = get_state,

    .set_pause = set_pause,

    .write     = audio_write,

    .start     = start,

    .reset     = reset,

    .priv_size = sizeof(struct priv),

    .priv_defaults = &(const struct priv) { .waveheader = true },

    .options = (const struct m_option[]) {

        {"file", OPT_STRING(outputfilename), .flags = M_OPT_FILE},

        {"waveheader", OPT_BOOL(waveheader)},

        {"append", OPT_BOOL(append)},

        {0}

    },

    .options_prefix = "ao-pcm",

};