lavdev: add openal input device

1 files changed, 256 insertions, 0 deletions

diff --git a/libavdevice/openal-dec.c b/libavdevice/openal-dec.c
new file mode 100644
index 0000000000..f01dff7d87
--- /dev/null
+++ b/libavdevice/openal-dec.c
@@ -0,0 +1,256 @@
+/*
+ * Copyright (c) 2011 Jonathan Baldwin
+ *
+ * This file is part of FFmpeg.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+/**
+ * @file
+ * OpenAL 1.1 capture device for libavdevice
+ **/
+
+#include <AL/al.h>
+#include <AL/alc.h>
+
+#include "libavutil/opt.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 CodecID 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, CODEC_ID_PCM_U8, 1},
+        [AL_FORMAT_MONO16-LOWEST_AL_FORMAT]   = {AL_FORMAT_MONO16, AV_NE (CODEC_ID_PCM_S16BE, CODEC_ID_PCM_S16LE), 1},
+        [AL_FORMAT_STEREO8-LOWEST_AL_FORMAT]  = {AL_FORMAT_STEREO8, CODEC_ID_PCM_U8, 2},
+        [AL_FORMAT_STEREO16-LOWEST_AL_FORMAT] = {AL_FORMAT_STEREO16, AV_NE (CODEC_ID_PCM_S16BE, 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, AVFormatParameters *ap)
+{
+    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 = av_new_stream(ctx, 0))) {
+        error = AVERROR(ENOMEM);
+        goto fail;
+    }
+
+    /* We work in microseconds */
+    av_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),     FF_OPT_TYPE_INT, {.dbl=2},     1, 2,      AV_OPT_FLAG_DECODING_PARAM },
+    {"sample_rate", "set sample rate",         OFFSET(sample_rate),  FF_OPT_TYPE_INT, {.dbl=44100}, 1, 192000, AV_OPT_FLAG_DECODING_PARAM },
+    {"sample_size", "set sample size",         OFFSET(sample_size),  FF_OPT_TYPE_INT, {.dbl=16},    8, 16,     AV_OPT_FLAG_DECODING_PARAM },
+    {"list_devices", "list available devices", OFFSET(list_devices), FF_OPT_TYPE_INT, {.dbl=0},     0, 1,      AV_OPT_FLAG_DECODING_PARAM },
+    {"true",  "", 0, FF_OPT_TYPE_CONST, {.dbl=1}, 0, 0, AV_OPT_FLAG_DECODING_PARAM, "list_devices" },
+    {"false", "", 0, FF_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
+};