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83 lines
3.0 KiB
C++
83 lines
3.0 KiB
C++
/* ---------------------------------------------------------------------------
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** This software is in the public domain, furnished "as is", without technical
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** support, and with no warranty, express or implied, as to its usefulness for
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** any purpose.
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**
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** ALSACapture.cpp
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**
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** V4L2 RTSP streamer
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**
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** ALSA capture overide of V4l2Capture
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**
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** -------------------------------------------------------------------------*/
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#include <alsa/asoundlib.h>
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class ALSACapture : public V4l2Capture
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{
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public:
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static ALSACapture* createNew(V4L2DeviceParameters params) { return new ALSACapture(params); }
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virtual ~ALSACapture()
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{
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if (m_pcm != NULL)
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{
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snd_pcm_close (m_pcm);
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}
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}
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protected:
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ALSACapture(V4L2DeviceParameters params) : V4l2Device(params,V4L2_BUF_TYPE_VIDEO_CAPTURE), V4l2Capture(params), m_pcm(NULL)
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{
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snd_pcm_hw_params_t *hw_params = NULL;
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int err = 0;
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unsigned int rate = 44100;
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// open PCM device
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if ((err = snd_pcm_open (&m_pcm, params.m_devName.c_str(), SND_PCM_STREAM_CAPTURE, 0)) < 0) {
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fprintf (stderr, "cannot open audio device %s (%s)\n", params.m_devName.c_str(), snd_strerror (err));
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}
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// configure hw_params
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else if ((err = snd_pcm_hw_params_malloc (&hw_params)) < 0) {
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fprintf (stderr, "cannot allocate hardware parameter structure (%s)\n", snd_strerror (err));
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}
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else if ((err = snd_pcm_hw_params_any (m_pcm, hw_params)) < 0) {
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fprintf (stderr, "cannot initialize hardware parameter structure (%s)\n", snd_strerror (err));
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}
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else if ((err = snd_pcm_hw_params_set_access (m_pcm, hw_params, SND_PCM_ACCESS_RW_INTERLEAVED)) < 0) {
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fprintf (stderr, "cannot set access type (%s)\n", snd_strerror (err));
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}
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else if ((err = snd_pcm_hw_params_set_format (m_pcm, hw_params, SND_PCM_FORMAT_S16_BE)) < 0) {
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fprintf (stderr, "cannot set sample format (%s)\n", snd_strerror (err));
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}
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else if ((err = snd_pcm_hw_params_set_rate_near (m_pcm, hw_params, &rate, 0)) < 0) {
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fprintf (stderr, "cannot set sample rate (%s)\n", snd_strerror (err));
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}
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else if ((err = snd_pcm_hw_params_set_channels (m_pcm, hw_params, 2)) < 0) {
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fprintf (stderr, "cannot set channel count (%s)\n", snd_strerror (err));
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}
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else if ((err = snd_pcm_hw_params (m_pcm, hw_params)) < 0) {
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fprintf (stderr, "cannot set parameters (%s)\n", snd_strerror (err));
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}
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// start capture
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else if ((err = snd_pcm_prepare (m_pcm)) < 0) {
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fprintf (stderr, "cannot prepare audio interface for use (%s)\n", snd_strerror (err));
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}
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}
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public:
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virtual size_t read(char* buffer, size_t bufferSize)
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{
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size_t ret = snd_pcm_readi (m_pcm, buffer, bufferSize);
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fprintf (stderr, "snd_pcm_readi size:%ld\n", ret);
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return ret;
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}
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virtual bool isReady() { return (m_pcm != NULL); };
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private:
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snd_pcm_t* m_pcm;
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};
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