mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-12-28 20:53:54 +02:00
252 lines
8.2 KiB
C
252 lines
8.2 KiB
C
/*
|
|
* Copyright (c) 2011 Jonathan Baldwin
|
|
*
|
|
* This file is part of FFmpeg.
|
|
*
|
|
* Permission to use, copy, modify, and/or distribute this software for any
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice and this permission notice appear in all copies.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
|
|
* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
|
|
* AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
|
|
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
|
|
* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
|
|
* OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
|
|
* PERFORMANCE OF THIS SOFTWARE.
|
|
*/
|
|
|
|
/**
|
|
* @file
|
|
* OpenAL 1.1 capture device for libavdevice
|
|
**/
|
|
|
|
#include <AL/al.h>
|
|
#include <AL/alc.h>
|
|
|
|
#include "libavutil/opt.h"
|
|
#include "libavformat/internal.h"
|
|
#include "avdevice.h"
|
|
|
|
typedef struct {
|
|
AVClass *class;
|
|
/** OpenAL capture device context. **/
|
|
ALCdevice *device;
|
|
/** The number of channels in the captured audio. **/
|
|
int channels;
|
|
/** The sample rate (in Hz) of the captured audio. **/
|
|
int sample_rate;
|
|
/** The sample size (in bits) of the captured audio. **/
|
|
int sample_size;
|
|
/** The OpenAL sample format of the captured audio. **/
|
|
ALCenum sample_format;
|
|
/** The number of bytes between two consecutive samples of the same channel/component. **/
|
|
ALCint sample_step;
|
|
/** If true, print a list of capture devices on this system and exit. **/
|
|
int list_devices;
|
|
} al_data;
|
|
|
|
typedef struct {
|
|
ALCenum al_fmt;
|
|
enum AVCodecID codec_id;
|
|
int channels;
|
|
} al_format_info;
|
|
|
|
#define LOWEST_AL_FORMAT FFMIN(FFMIN(AL_FORMAT_MONO8,AL_FORMAT_MONO16),FFMIN(AL_FORMAT_STEREO8,AL_FORMAT_STEREO16))
|
|
|
|
/**
|
|
* Get information about an AL_FORMAT value.
|
|
* @param al_fmt the AL_FORMAT value to find information about.
|
|
* @return A pointer to a structure containing information about the AL_FORMAT value.
|
|
*/
|
|
static inline al_format_info* get_al_format_info(ALCenum al_fmt)
|
|
{
|
|
static al_format_info info_table[] = {
|
|
[AL_FORMAT_MONO8-LOWEST_AL_FORMAT] = {AL_FORMAT_MONO8, AV_CODEC_ID_PCM_U8, 1},
|
|
[AL_FORMAT_MONO16-LOWEST_AL_FORMAT] = {AL_FORMAT_MONO16, AV_NE (AV_CODEC_ID_PCM_S16BE, AV_CODEC_ID_PCM_S16LE), 1},
|
|
[AL_FORMAT_STEREO8-LOWEST_AL_FORMAT] = {AL_FORMAT_STEREO8, AV_CODEC_ID_PCM_U8, 2},
|
|
[AL_FORMAT_STEREO16-LOWEST_AL_FORMAT] = {AL_FORMAT_STEREO16, AV_NE (AV_CODEC_ID_PCM_S16BE, AV_CODEC_ID_PCM_S16LE), 2},
|
|
};
|
|
|
|
return &info_table[al_fmt-LOWEST_AL_FORMAT];
|
|
}
|
|
|
|
/**
|
|
* Get the OpenAL error code, translated into an av/errno error code.
|
|
* @param device The ALC device to check for errors.
|
|
* @param error_msg_ret A pointer to a char* in which to return the error message, or NULL if desired.
|
|
* @return The error code, or 0 if there is no error.
|
|
*/
|
|
static inline int al_get_error(ALCdevice *device, const char** error_msg_ret)
|
|
{
|
|
ALCenum error = alcGetError(device);
|
|
if (error_msg_ret)
|
|
*error_msg_ret = (const char*) alcGetString(device, error);
|
|
switch (error) {
|
|
case ALC_NO_ERROR:
|
|
return 0;
|
|
case ALC_INVALID_DEVICE:
|
|
return AVERROR(ENODEV);
|
|
break;
|
|
case ALC_INVALID_CONTEXT:
|
|
case ALC_INVALID_ENUM:
|
|
case ALC_INVALID_VALUE:
|
|
return AVERROR(EINVAL);
|
|
break;
|
|
case ALC_OUT_OF_MEMORY:
|
|
return AVERROR(ENOMEM);
|
|
break;
|
|
default:
|
|
return AVERROR(EIO);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Print out a list of OpenAL capture devices on this system.
|
|
*/
|
|
static inline void print_al_capture_devices(void *log_ctx)
|
|
{
|
|
const char *devices;
|
|
|
|
if (!(devices = alcGetString(NULL, ALC_CAPTURE_DEVICE_SPECIFIER)))
|
|
return;
|
|
|
|
av_log(log_ctx, AV_LOG_INFO, "List of OpenAL capture devices on this system:\n");
|
|
|
|
for (; *devices != '\0'; devices += strlen(devices) + 1)
|
|
av_log(log_ctx, AV_LOG_INFO, " %s\n", devices);
|
|
}
|
|
|
|
static int read_header(AVFormatContext *ctx)
|
|
{
|
|
al_data *ad = ctx->priv_data;
|
|
static const ALCenum sample_formats[2][2] = {
|
|
{ AL_FORMAT_MONO8, AL_FORMAT_STEREO8 },
|
|
{ AL_FORMAT_MONO16, AL_FORMAT_STEREO16 }
|
|
};
|
|
int error = 0;
|
|
const char *error_msg;
|
|
AVStream *st = NULL;
|
|
AVCodecContext *codec = NULL;
|
|
|
|
if (ad->list_devices) {
|
|
print_al_capture_devices(ctx);
|
|
return AVERROR_EXIT;
|
|
}
|
|
|
|
ad->sample_format = sample_formats[ad->sample_size/8-1][ad->channels-1];
|
|
|
|
/* Open device for capture */
|
|
ad->device =
|
|
alcCaptureOpenDevice(ctx->filename[0] ? ctx->filename : NULL,
|
|
ad->sample_rate,
|
|
ad->sample_format,
|
|
ad->sample_rate); /* Maximum 1 second of sample data to be read at once */
|
|
|
|
if (error = al_get_error(ad->device, &error_msg)) goto fail;
|
|
|
|
/* Create stream */
|
|
if (!(st = avformat_new_stream(ctx, NULL))) {
|
|
error = AVERROR(ENOMEM);
|
|
goto fail;
|
|
}
|
|
|
|
/* We work in microseconds */
|
|
avpriv_set_pts_info(st, 64, 1, 1000000);
|
|
|
|
/* Set codec parameters */
|
|
codec = st->codec;
|
|
codec->codec_type = AVMEDIA_TYPE_AUDIO;
|
|
codec->sample_rate = ad->sample_rate;
|
|
codec->channels = get_al_format_info(ad->sample_format)->channels;
|
|
codec->codec_id = get_al_format_info(ad->sample_format)->codec_id;
|
|
|
|
/* This is needed to read the audio data */
|
|
ad->sample_step = (av_get_bits_per_sample(get_al_format_info(ad->sample_format)->codec_id) *
|
|
get_al_format_info(ad->sample_format)->channels) / 8;
|
|
|
|
/* Finally, start the capture process */
|
|
alcCaptureStart(ad->device);
|
|
|
|
return 0;
|
|
|
|
fail:
|
|
/* Handle failure */
|
|
if (ad->device)
|
|
alcCaptureCloseDevice(ad->device);
|
|
if (error_msg)
|
|
av_log(ctx, AV_LOG_ERROR, "Cannot open device: %s\n", error_msg);
|
|
return error;
|
|
}
|
|
|
|
static int read_packet(AVFormatContext* ctx, AVPacket *pkt)
|
|
{
|
|
al_data *ad = ctx->priv_data;
|
|
int error=0;
|
|
const char *error_msg;
|
|
ALCint nb_samples;
|
|
|
|
/* Get number of samples available */
|
|
alcGetIntegerv(ad->device, ALC_CAPTURE_SAMPLES, (ALCsizei) sizeof(ALCint), &nb_samples);
|
|
if (error = al_get_error(ad->device, &error_msg)) goto fail;
|
|
|
|
/* Create a packet of appropriate size */
|
|
av_new_packet(pkt, nb_samples*ad->sample_step);
|
|
pkt->pts = av_gettime();
|
|
|
|
/* Fill the packet with the available samples */
|
|
alcCaptureSamples(ad->device, pkt->data, nb_samples);
|
|
if (error = al_get_error(ad->device, &error_msg)) goto fail;
|
|
|
|
return pkt->size;
|
|
fail:
|
|
/* Handle failure */
|
|
if (pkt->data)
|
|
av_destruct_packet(pkt);
|
|
if (error_msg)
|
|
av_log(ctx, AV_LOG_ERROR, "Error: %s\n", error_msg);
|
|
return error;
|
|
}
|
|
|
|
static int read_close(AVFormatContext* ctx)
|
|
{
|
|
al_data *ad = ctx->priv_data;
|
|
|
|
if (ad->device) {
|
|
alcCaptureStop(ad->device);
|
|
alcCaptureCloseDevice(ad->device);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
#define OFFSET(x) offsetof(al_data, x)
|
|
|
|
static const AVOption options[] = {
|
|
{"channels", "set number of channels", OFFSET(channels), AV_OPT_TYPE_INT, {.dbl=2}, 1, 2, AV_OPT_FLAG_DECODING_PARAM },
|
|
{"sample_rate", "set sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT, {.dbl=44100}, 1, 192000, AV_OPT_FLAG_DECODING_PARAM },
|
|
{"sample_size", "set sample size", OFFSET(sample_size), AV_OPT_TYPE_INT, {.dbl=16}, 8, 16, AV_OPT_FLAG_DECODING_PARAM },
|
|
{"list_devices", "list available devices", OFFSET(list_devices), AV_OPT_TYPE_INT, {.dbl=0}, 0, 1, AV_OPT_FLAG_DECODING_PARAM, "list_devices" },
|
|
{"true", "", 0, AV_OPT_TYPE_CONST, {.dbl=1}, 0, 0, AV_OPT_FLAG_DECODING_PARAM, "list_devices" },
|
|
{"false", "", 0, AV_OPT_TYPE_CONST, {.dbl=0}, 0, 0, AV_OPT_FLAG_DECODING_PARAM, "list_devices" },
|
|
{NULL},
|
|
};
|
|
|
|
static const AVClass class = {
|
|
.class_name = "openal",
|
|
.item_name = av_default_item_name,
|
|
.option = options,
|
|
.version = LIBAVUTIL_VERSION_INT
|
|
};
|
|
|
|
AVInputFormat ff_openal_demuxer = {
|
|
.name = "openal",
|
|
.long_name = NULL_IF_CONFIG_SMALL("OpenAL audio capture device"),
|
|
.priv_data_size = sizeof(al_data),
|
|
.read_probe = NULL,
|
|
.read_header = read_header,
|
|
.read_packet = read_packet,
|
|
.read_close = read_close,
|
|
.flags = AVFMT_NOFILE,
|
|
.priv_class = &class
|
|
};
|