/* * Linux audio play and grab interface * Copyright (c) 2000, 2001 Fabrice Bellard * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "config.h" #include <string.h> #if HAVE_UNISTD_H#include <unistd.h>#endif#include <fcntl.h>#include <sys/ioctl.h>#include <sys/soundcard.h> #include "libavutil/file_open.h"#include "libavutil/log.h" #include "avdevice.h" #include "oss.h" int ff_oss_audio_open(AVFormatContext *s1, int is_output,                      const char *audio_device){    OSSAudioData *s = s1->priv_data;    int audio_fd;    int tmp, err;    char *flip = getenv("AUDIO_FLIP_LEFT");     if (is_output)        audio_fd = avpriv_open(audio_device, O_WRONLY);    else        audio_fd = avpriv_open(audio_device, O_RDONLY);    if (audio_fd < 0) {        av_log(s1, AV_LOG_ERROR, "%s: %s\n", audio_device, av_err2str(AVERROR(errno)));        return AVERROR(EIO);    }     if (flip && *flip == '1') {        s->flip_left = 1;    }     /* non blocking mode */    if (!is_output) {        if (fcntl(audio_fd, F_SETFL, O_NONBLOCK) < 0) {            av_log(s1, AV_LOG_WARNING, "%s: Could not enable non block mode (%s)\n", audio_device, av_err2str(AVERROR(errno)));        }    }     s->frame_size = OSS_AUDIO_BLOCK_SIZE; #define CHECK_IOCTL_ERROR(event)                                              \    if (err < 0) {                                                            \        av_log(s1, AV_LOG_ERROR, #event ": %s\n", av_err2str(AVERROR(errno)));\        goto fail;                                                            \    }     /* select format : favour native format     * We don't CHECK_IOCTL_ERROR here because even if failed OSS still may be     * usable. If OSS is not usable the SNDCTL_DSP_SETFMTS later is going to     * fail anyway. */    err = ioctl(audio_fd, SNDCTL_DSP_GETFMTS, &tmp);    if (err < 0) {        av_log(s1, AV_LOG_WARNING, "SNDCTL_DSP_GETFMTS: %s\n", av_err2str(AVERROR(errno)));    } #if HAVE_BIGENDIAN    if (tmp & AFMT_S16_BE) {        tmp = AFMT_S16_BE;    } else if (tmp & AFMT_S16_LE) {        tmp = AFMT_S16_LE;    } else {        tmp = 0;    }#else    if (tmp & AFMT_S16_LE) {        tmp = AFMT_S16_LE;    } else if (tmp & AFMT_S16_BE) {        tmp = AFMT_S16_BE;    } else {        tmp = 0;    }#endif     switch(tmp) {    case AFMT_S16_LE:        s->codec_id = AV_CODEC_ID_PCM_S16LE;        s->sample_size = 2;        break;    case AFMT_S16_BE:        s->codec_id = AV_CODEC_ID_PCM_S16BE;        s->sample_size = 2;        break;    default:        av_log(s1, AV_LOG_ERROR, "Soundcard does not support 16 bit sample format\n");        close(audio_fd);        return AVERROR(EIO);    }    err=ioctl(audio_fd, SNDCTL_DSP_SETFMT, &tmp);    CHECK_IOCTL_ERROR(SNDCTL_DSP_SETFMT)     tmp = (s->channels == 2);    err = ioctl(audio_fd, SNDCTL_DSP_STEREO, &tmp);    CHECK_IOCTL_ERROR(SNDCTL_DSP_STEREO)     tmp = s->sample_rate;    err = ioctl(audio_fd, SNDCTL_DSP_SPEED, &tmp);    CHECK_IOCTL_ERROR(SNDCTL_DSP_SPEED)    s->sample_rate = tmp; /* store real sample rate */    s->fd = audio_fd;     return 0; fail:    close(audio_fd);    return AVERROR(EIO);#undef CHECK_IOCTL_ERROR} int ff_oss_audio_close(OSSAudioData *s){    close(s->fd);    return 0;}