Android录制声音(二)录音输输出格式

在上一篇的学习中发现，android在设定录音的编码时需要同时设置录音的输出格式，当时不知道怎样的编码对着怎样的格式，最近在看sdk时发现了一点

Table 1. Core media format and codec support.

Type	Format / Codec	Encoder	Decoder	Details	Supported File Type(s) / Container Formats
Audio	AAC LC/LTP	•	•	Mono/Stereo content in any combination of standard bit rates up to 160 kbps and sampling rates from 8 to 48kHz	• 3GPP (.3gp) • MPEG-4 (.mp4, .m4a) • ADTS raw AAC (.aac, decode in Android 3.1+, encode in Android 4.0+, ADIF not supported) • MPEG-TS (.ts, not seekable, Android 3.0+)
HE-AACv1 (AAC+)		•
HE-AACv2 (enhanced AAC+)		•
AMR-NB	•	•	4.75 to 12.2 kbps sampled @ 8kHz	3GPP (.3gp)
AMR-WB	•	•	9 rates from 6.60 kbit/s to 23.85 kbit/s sampled @ 16kHz	3GPP (.3gp)
FLAC		• (Android 3.1+)	Mono/Stereo (no multichannel). Sample rates up to 48 kHz (but up to 44.1 kHz is recommended on devices with 44.1 kHz output, as the 48 to 44.1 kHz downsampler does not include a low-pass filter). 16-bit recommended; no dither applied for 24-bit.	FLAC (.flac) only
MP3		•	Mono/Stereo 8-320Kbps constant (CBR) or variable bit-rate (VBR)	MP3 (.mp3)
MIDI		•	MIDI Type 0 and 1. DLS Version 1 and 2. XMF and Mobile XMF. Support for ringtone formats RTTTL/RTX, OTA, and iMelody	• Type 0 and 1 (.mid, .xmf, .mxmf) • RTTTL/RTX (.rtttl, .rtx) • OTA (.ota) • iMelody (.imy)
Vorbis		•		• Ogg (.ogg) • Matroska (.mkv, Android 4.0+)
PCM/WAVE		•	8- and 16-bit linear PCM (rates up to limit of hardware)	WAVE (.wav)
Image	JPEG	•	•	Base+progressive	JPEG (.jpg)
GIF		•		GIF (.gif)
PNG	•	•		PNG (.png)
BMP		•		BMP (.bmp)
WEBP	• (Android 4.0+)	• (Android 4.0+)		WebP (.webp)
Video	H.263	•	•		• 3GPP (.3gp) • MPEG-4 (.mp4)
H.264 AVC	• (Android 3.0+)	•	Baseline Profile (BP)	• 3GPP (.3gp) • MPEG-4 (.mp4) • MPEG-TS (.ts, AAC audio only, not seekable, Android 3.0+)
MPEG-4 SP		•		3GPP (.3gp)
VP8		• (Android 2.3.3+)	Streamable only in Android 4.0 and above	• WebM (.webm) • Matroska (.mkv, Android 4.0+)

Video Encoding Recommendations

Table 2, below, lists examples of video encoding profiles and parameters that the Android media framework supports for playback. In addition to these encoding parameter recommendations, a device's availablevideo recording profiles can be used as
a proxy for media playback capabilities. These profiles can be inspected using the

CamcorderProfile

class, which is available since API level 8.

Table 2. Examples of supported video encoding parameters.

	SD (Low quality)	SD (High quality)	HD (Not available on all devices)
Video codec	H.264 Baseline Profile	H.264 Baseline Profile	H.264 Baseline Profile
Video resolution	176 x 144 px	480 x 360 px	1280 x 720 px
Video frame rate	12 fps	30 fps	30 fps
Video bitrate	56 Kbps	500 Kbps	2 Mbps
Audio codec	AAC-LC	AAC-LC	AAC-LC
Audio channels	1 (mono)	2 (stereo)	2 (stereo)
Audio bitrate	24 Kbps	128 Kbps	192 Kbps

For video content that is streamed over HTTP or RTSP, there are additional requirements: