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- /*
- * 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 "libavutil/time.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 */
- if ((error = av_new_packet(pkt, nb_samples*ad->sample_step)) < 0)
- goto fail;
- 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, {.i64=2}, 1, 2, AV_OPT_FLAG_DECODING_PARAM },
- {"sample_rate", "set sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64=44100}, 1, 192000, AV_OPT_FLAG_DECODING_PARAM },
- {"sample_size", "set sample size", OFFSET(sample_size), AV_OPT_TYPE_INT, {.i64=16}, 8, 16, AV_OPT_FLAG_DECODING_PARAM },
- {"list_devices", "list available devices", OFFSET(list_devices), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, AV_OPT_FLAG_DECODING_PARAM, "list_devices" },
- {"true", "", 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, AV_OPT_FLAG_DECODING_PARAM, "list_devices" },
- {"false", "", 0, AV_OPT_TYPE_CONST, {.i64=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,
- .category = AV_CLASS_CATEGORY_DEVICE_AUDIO_INPUT,
- };
- 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
- };
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