oss_audio.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_SOUNDCARD_H
  24. #include <soundcard.h>
  25. #else
  26. #include <sys/soundcard.h>
  27. #endif
  28. #if HAVE_UNISTD_H
  29. #include <unistd.h>
  30. #endif
  31. #include <fcntl.h>
  32. #include <sys/ioctl.h>
  33. #include "libavutil/log.h"
  34. #include "libavcodec/avcodec.h"
  35. #include "avdevice.h"
  36. #include "oss_audio.h"
  37. int ff_oss_audio_open(AVFormatContext *s1, int is_output,
  38. const char *audio_device)
  39. {
  40. OSSAudioData *s = s1->priv_data;
  41. int audio_fd;
  42. int tmp, err;
  43. char *flip = getenv("AUDIO_FLIP_LEFT");
  44. if (is_output)
  45. audio_fd = avpriv_open(audio_device, O_WRONLY);
  46. else
  47. audio_fd = avpriv_open(audio_device, O_RDONLY);
  48. if (audio_fd < 0) {
  49. av_log(s1, AV_LOG_ERROR, "%s: %s\n", audio_device, av_err2str(AVERROR(errno)));
  50. return AVERROR(EIO);
  51. }
  52. if (flip && *flip == '1') {
  53. s->flip_left = 1;
  54. }
  55. /* non blocking mode */
  56. if (!is_output) {
  57. if (fcntl(audio_fd, F_SETFL, O_NONBLOCK) < 0) {
  58. av_log(s1, AV_LOG_WARNING, "%s: Could not enable non block mode (%s)\n", audio_device, av_err2str(AVERROR(errno)));
  59. }
  60. }
  61. s->frame_size = OSS_AUDIO_BLOCK_SIZE;
  62. #define CHECK_IOCTL_ERROR(event) \
  63. if (err < 0) { \
  64. av_log(s1, AV_LOG_ERROR, #event ": %s\n", av_err2str(AVERROR(errno)));\
  65. goto fail; \
  66. }
  67. /* select format : favour native format
  68. * We don't CHECK_IOCTL_ERROR here because even if failed OSS still may be
  69. * usable. If OSS is not usable the SNDCTL_DSP_SETFMTS later is going to
  70. * fail anyway. */
  71. err = ioctl(audio_fd, SNDCTL_DSP_GETFMTS, &tmp);
  72. if (err < 0) {
  73. av_log(s1, AV_LOG_WARNING, "SNDCTL_DSP_GETFMTS: %s\n", av_err2str(AVERROR(errno)));
  74. }
  75. #if HAVE_BIGENDIAN
  76. if (tmp & AFMT_S16_BE) {
  77. tmp = AFMT_S16_BE;
  78. } else if (tmp & AFMT_S16_LE) {
  79. tmp = AFMT_S16_LE;
  80. } else {
  81. tmp = 0;
  82. }
  83. #else
  84. if (tmp & AFMT_S16_LE) {
  85. tmp = AFMT_S16_LE;
  86. } else if (tmp & AFMT_S16_BE) {
  87. tmp = AFMT_S16_BE;
  88. } else {
  89. tmp = 0;
  90. }
  91. #endif
  92. switch(tmp) {
  93. case AFMT_S16_LE:
  94. s->codec_id = AV_CODEC_ID_PCM_S16LE;
  95. break;
  96. case AFMT_S16_BE:
  97. s->codec_id = AV_CODEC_ID_PCM_S16BE;
  98. break;
  99. default:
  100. av_log(s1, AV_LOG_ERROR, "Soundcard does not support 16 bit sample format\n");
  101. close(audio_fd);
  102. return AVERROR(EIO);
  103. }
  104. err=ioctl(audio_fd, SNDCTL_DSP_SETFMT, &tmp);
  105. CHECK_IOCTL_ERROR(SNDCTL_DSP_SETFMTS)
  106. tmp = (s->channels == 2);
  107. err = ioctl(audio_fd, SNDCTL_DSP_STEREO, &tmp);
  108. CHECK_IOCTL_ERROR(SNDCTL_DSP_STEREO)
  109. tmp = s->sample_rate;
  110. err = ioctl(audio_fd, SNDCTL_DSP_SPEED, &tmp);
  111. CHECK_IOCTL_ERROR(SNDCTL_DSP_SPEED)
  112. s->sample_rate = tmp; /* store real sample rate */
  113. s->fd = audio_fd;
  114. return 0;
  115. fail:
  116. close(audio_fd);
  117. return AVERROR(EIO);
  118. #undef CHECK_IOCTL_ERROR
  119. }
  120. int ff_oss_audio_close(OSSAudioData *s)
  121. {
  122. close(s->fd);
  123. return 0;
  124. }