summaryrefslogtreecommitdiff
path: root/libavdevice/openal-dec.c
diff options
context:
space:
mode:
Diffstat (limited to 'libavdevice/openal-dec.c')
-rw-r--r--libavdevice/openal-dec.c254
1 files changed, 254 insertions, 0 deletions
diff --git a/libavdevice/openal-dec.c b/libavdevice/openal-dec.c
new file mode 100644
index 0000000000..b552158f76
--- /dev/null
+++ b/libavdevice/openal-dec.c
@@ -0,0 +1,254 @@
+/*
+ * 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 const inline al_format_info* get_al_format_info(ALCenum al_fmt)
+{
+ static const 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
+};
View Lorry Controller Status