oss.c 3.9 KB

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  1. /*
  2. * Linux audio play and grab interface
  3. * Copyright (c) 2000, 2001 Fabrice Bellard
  4. *
  5. * This file is part of FFmpeg.
  6. *
  7. * FFmpeg is free software; you can redistribute it and/or
  8. * modify it under the terms of the GNU Lesser General Public
  9. * License as published by the Free Software Foundation; either
  10. * version 2.1 of the License, or (at your option) any later version.
  11. *
  12. * FFmpeg is distributed in the hope that it will be useful,
  13. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15. * Lesser General Public License for more details.
  16. *
  17. * You should have received a copy of the GNU Lesser General Public
  18. * License along with FFmpeg; if not, write to the Free Software
  19. * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20. */
  21. #include "config.h"
  22. #include <string.h>
  23. #if HAVE_UNISTD_H
  24. #include <unistd.h>
  25. #endif
  26. #include <fcntl.h>
  27. #include <sys/ioctl.h>
  28. #include <sys/soundcard.h>
  29. #include "libavutil/log.h"
  30. #include "libavcodec/avcodec.h"
  31. #include "avdevice.h"
  32. #include "oss.h"
  33. int ff_oss_audio_open(AVFormatContext *s1, int is_output,
  34. const char *audio_device)
  35. {
  36. OSSAudioData *s = s1->priv_data;
  37. int audio_fd;
  38. int tmp, err;
  39. char *flip = getenv("AUDIO_FLIP_LEFT");
  40. if (is_output)
  41. audio_fd = avpriv_open(audio_device, O_WRONLY);
  42. else
  43. audio_fd = avpriv_open(audio_device, O_RDONLY);
  44. if (audio_fd < 0) {
  45. av_log(s1, AV_LOG_ERROR, "%s: %s\n", audio_device, av_err2str(AVERROR(errno)));
  46. return AVERROR(EIO);
  47. }
  48. if (flip && *flip == '1') {
  49. s->flip_left = 1;
  50. }
  51. /* non blocking mode */
  52. if (!is_output) {
  53. if (fcntl(audio_fd, F_SETFL, O_NONBLOCK) < 0) {
  54. av_log(s1, AV_LOG_WARNING, "%s: Could not enable non block mode (%s)\n", audio_device, av_err2str(AVERROR(errno)));
  55. }
  56. }
  57. s->frame_size = OSS_AUDIO_BLOCK_SIZE;
  58. #define CHECK_IOCTL_ERROR(event) \
  59. if (err < 0) { \
  60. av_log(s1, AV_LOG_ERROR, #event ": %s\n", av_err2str(AVERROR(errno)));\
  61. goto fail; \
  62. }
  63. /* select format : favour native format
  64. * We don't CHECK_IOCTL_ERROR here because even if failed OSS still may be
  65. * usable. If OSS is not usable the SNDCTL_DSP_SETFMTS later is going to
  66. * fail anyway. */
  67. err = ioctl(audio_fd, SNDCTL_DSP_GETFMTS, &tmp);
  68. if (err < 0) {
  69. av_log(s1, AV_LOG_WARNING, "SNDCTL_DSP_GETFMTS: %s\n", av_err2str(AVERROR(errno)));
  70. }
  71. #if HAVE_BIGENDIAN
  72. if (tmp & AFMT_S16_BE) {
  73. tmp = AFMT_S16_BE;
  74. } else if (tmp & AFMT_S16_LE) {
  75. tmp = AFMT_S16_LE;
  76. } else {
  77. tmp = 0;
  78. }
  79. #else
  80. if (tmp & AFMT_S16_LE) {
  81. tmp = AFMT_S16_LE;
  82. } else if (tmp & AFMT_S16_BE) {
  83. tmp = AFMT_S16_BE;
  84. } else {
  85. tmp = 0;
  86. }
  87. #endif
  88. switch(tmp) {
  89. case AFMT_S16_LE:
  90. s->codec_id = AV_CODEC_ID_PCM_S16LE;
  91. break;
  92. case AFMT_S16_BE:
  93. s->codec_id = AV_CODEC_ID_PCM_S16BE;
  94. break;
  95. default:
  96. av_log(s1, AV_LOG_ERROR, "Soundcard does not support 16 bit sample format\n");
  97. close(audio_fd);
  98. return AVERROR(EIO);
  99. }
  100. err=ioctl(audio_fd, SNDCTL_DSP_SETFMT, &tmp);
  101. CHECK_IOCTL_ERROR(SNDCTL_DSP_SETFMTS)
  102. tmp = (s->channels == 2);
  103. err = ioctl(audio_fd, SNDCTL_DSP_STEREO, &tmp);
  104. CHECK_IOCTL_ERROR(SNDCTL_DSP_STEREO)
  105. tmp = s->sample_rate;
  106. err = ioctl(audio_fd, SNDCTL_DSP_SPEED, &tmp);
  107. CHECK_IOCTL_ERROR(SNDCTL_DSP_SPEED)
  108. s->sample_rate = tmp; /* store real sample rate */
  109. s->fd = audio_fd;
  110. return 0;
  111. fail:
  112. close(audio_fd);
  113. return AVERROR(EIO);
  114. #undef CHECK_IOCTL_ERROR
  115. }
  116. int ff_oss_audio_close(OSSAudioData *s)
  117. {
  118. close(s->fd);
  119. return 0;
  120. }