| /* |
| * ALSA input and output |
| * Copyright (c) 2007 Luca Abeni ( lucabe72 email it ) |
| * Copyright (c) 2007 Benoit Fouet ( benoit fouet free fr ) |
| * |
| * 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 |
| */ |
| |
| /** |
| * @file libavdevice/alsa-audio-common.c |
| * ALSA input and output: common code |
| * @author Luca Abeni ( lucabe72 email it ) |
| * @author Benoit Fouet ( benoit fouet free fr ) |
| * @author Nicolas George ( nicolas george normalesup org ) |
| */ |
| |
| #include "libavformat/avformat.h" |
| #include <alsa/asoundlib.h> |
| |
| #include "alsa-audio.h" |
| |
| static av_cold snd_pcm_format_t codec_id_to_pcm_format(int codec_id) |
| { |
| switch(codec_id) { |
| case CODEC_ID_PCM_S16LE: return SND_PCM_FORMAT_S16_LE; |
| case CODEC_ID_PCM_S16BE: return SND_PCM_FORMAT_S16_BE; |
| case CODEC_ID_PCM_S8: return SND_PCM_FORMAT_S8; |
| default: return SND_PCM_FORMAT_UNKNOWN; |
| } |
| } |
| |
| av_cold int ff_alsa_open(AVFormatContext *ctx, int mode, |
| unsigned int *sample_rate, |
| int channels, int *codec_id) |
| { |
| AlsaData *s = ctx->priv_data; |
| const char *audio_device; |
| int res, flags = 0; |
| snd_pcm_format_t format; |
| snd_pcm_t *h; |
| snd_pcm_hw_params_t *hw_params; |
| snd_pcm_uframes_t buffer_size, period_size; |
| |
| if (ctx->filename[0] == 0) audio_device = "default"; |
| else audio_device = ctx->filename; |
| |
| if (*codec_id == CODEC_ID_NONE) |
| *codec_id = DEFAULT_CODEC_ID; |
| format = codec_id_to_pcm_format(*codec_id); |
| if (format == SND_PCM_FORMAT_UNKNOWN) { |
| av_log(ctx, AV_LOG_ERROR, "sample format 0x%04x is not supported\n", *codec_id); |
| return AVERROR(ENOSYS); |
| } |
| s->frame_size = av_get_bits_per_sample(*codec_id) / 8 * channels; |
| |
| if (ctx->flags & AVFMT_FLAG_NONBLOCK) { |
| flags = O_NONBLOCK; |
| } |
| res = snd_pcm_open(&h, audio_device, mode, flags); |
| if (res < 0) { |
| av_log(ctx, AV_LOG_ERROR, "cannot open audio device %s (%s)\n", |
| audio_device, snd_strerror(res)); |
| return AVERROR_IO; |
| } |
| |
| res = snd_pcm_hw_params_malloc(&hw_params); |
| if (res < 0) { |
| av_log(ctx, AV_LOG_ERROR, "cannot allocate hardware parameter structure (%s)\n", |
| snd_strerror(res)); |
| goto fail1; |
| } |
| |
| res = snd_pcm_hw_params_any(h, hw_params); |
| if (res < 0) { |
| av_log(ctx, AV_LOG_ERROR, "cannot initialize hardware parameter structure (%s)\n", |
| snd_strerror(res)); |
| goto fail; |
| } |
| |
| res = snd_pcm_hw_params_set_access(h, hw_params, SND_PCM_ACCESS_RW_INTERLEAVED); |
| if (res < 0) { |
| av_log(ctx, AV_LOG_ERROR, "cannot set access type (%s)\n", |
| snd_strerror(res)); |
| goto fail; |
| } |
| |
| res = snd_pcm_hw_params_set_format(h, hw_params, format); |
| if (res < 0) { |
| av_log(ctx, AV_LOG_ERROR, "cannot set sample format 0x%04x %d (%s)\n", |
| *codec_id, format, snd_strerror(res)); |
| goto fail; |
| } |
| |
| res = snd_pcm_hw_params_set_rate_near(h, hw_params, sample_rate, 0); |
| if (res < 0) { |
| av_log(ctx, AV_LOG_ERROR, "cannot set sample rate (%s)\n", |
| snd_strerror(res)); |
| goto fail; |
| } |
| |
| res = snd_pcm_hw_params_set_channels(h, hw_params, channels); |
| if (res < 0) { |
| av_log(ctx, AV_LOG_ERROR, "cannot set channel count to %d (%s)\n", |
| channels, snd_strerror(res)); |
| goto fail; |
| } |
| |
| snd_pcm_hw_params_get_buffer_size_max(hw_params, &buffer_size); |
| /* TODO: maybe use ctx->max_picture_buffer somehow */ |
| res = snd_pcm_hw_params_set_buffer_size_near(h, hw_params, &buffer_size); |
| if (res < 0) { |
| av_log(ctx, AV_LOG_ERROR, "cannot set ALSA buffer size (%s)\n", |
| snd_strerror(res)); |
| goto fail; |
| } |
| |
| snd_pcm_hw_params_get_period_size_min(hw_params, &period_size, NULL); |
| res = snd_pcm_hw_params_set_period_size_near(h, hw_params, &period_size, NULL); |
| if (res < 0) { |
| av_log(ctx, AV_LOG_ERROR, "cannot set ALSA period size (%s)\n", |
| snd_strerror(res)); |
| goto fail; |
| } |
| s->period_size = period_size; |
| |
| res = snd_pcm_hw_params(h, hw_params); |
| if (res < 0) { |
| av_log(ctx, AV_LOG_ERROR, "cannot set parameters (%s)\n", |
| snd_strerror(res)); |
| goto fail; |
| } |
| |
| snd_pcm_hw_params_free(hw_params); |
| |
| s->h = h; |
| return 0; |
| |
| fail: |
| snd_pcm_hw_params_free(hw_params); |
| fail1: |
| snd_pcm_close(h); |
| return AVERROR_IO; |
| } |
| |
| av_cold int ff_alsa_close(AVFormatContext *s1) |
| { |
| AlsaData *s = s1->priv_data; |
| |
| snd_pcm_close(s->h); |
| return 0; |
| } |
| |
| int ff_alsa_xrun_recover(AVFormatContext *s1, int err) |
| { |
| AlsaData *s = s1->priv_data; |
| snd_pcm_t *handle = s->h; |
| |
| av_log(s1, AV_LOG_WARNING, "ALSA buffer xrun.\n"); |
| if (err == -EPIPE) { |
| err = snd_pcm_prepare(handle); |
| if (err < 0) { |
| av_log(s1, AV_LOG_ERROR, "cannot recover from underrun (snd_pcm_prepare failed: %s)\n", snd_strerror(err)); |
| |
| return AVERROR_IO; |
| } |
| } else if (err == -ESTRPIPE) { |
| av_log(s1, AV_LOG_ERROR, "-ESTRPIPE... Unsupported!\n"); |
| |
| return -1; |
| } |
| return err; |
| } |