AVInputFormat
1. AVInputFormat是demuxer或者indev
AVInputFormat *previn = NULL, *in;
for (int i = 0; (in = (AVInputFormat*)demuxer_list[i]); i++) {
if (previn)
previn->next = in;
previn = in;
}
if (indev_list) {
for (int i = 0; (in = (AVInputFormat*)indev_list[i]); i++) {
if (previn)
previn->next = in;
previn = in;
}
}
2. AVInputFormat的声明
typedef struct AVInputFormat {
/**
* A comma separated list of short names for the format. New names
* may be appended with a minor bump.
*/
const char *name;
/**
* Descriptive name for the format, meant to be more human-readable
* than name. You should use the NULL_IF_CONFIG_SMALL() macro
* to define it.
*/
const char *long_name;
/**
* Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS,
* AVFMT_NOTIMESTAMPS, AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH,
* AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK, AVFMT_SEEK_TO_PTS.
*/
int flags;
/**
* If extensions are defined, then no probe is done. You should
* usually not use extension format guessing because it is not
* reliable enough
*/
const char *extensions;
const struct AVCodecTag * const *codec_tag;
const AVClass *priv_class; ///< AVClass for the private context
/**
* Comma-separated list of mime types.
* It is used check for matching mime types while probing.
* @see av_probe_input_format2
*/
const char *mime_type;
/*****************************************************************
* No fields below this line are part of the public API. They
* may not be used outside of libavformat and can be changed and
* removed at will.
* New public fields should be added right above.
*****************************************************************
*/
ff_const59 struct AVInputFormat *next;
/**
* Raw demuxers store their codec ID here.
*/
int raw_codec_id;
/**
* Size of private data so that it can be allocated in the wrapper.
*/
int priv_data_size;
/**
* Tell if a given file has a chance of being parsed as this format.
* The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes
* big so you do not have to check for that unless you need more.
*/
int (*read_probe)(const AVProbeData *);
/**
* Read the format header and initialize the AVFormatContext
* structure. Return 0 if OK. 'avformat_new_stream' should be
* called to create new streams.
*/
int (*read_header)(struct AVFormatContext *);
/**
* Read one packet and put it in 'pkt'. pts and flags are also
* set. 'avformat_new_stream' can be called only if the flag
* AVFMTCTX_NOHEADER is used and only in the calling thread (not in a
* background thread).
* @return 0 on success, < 0 on error.
* When returning an error, pkt must not have been allocated
* or must be freed before returning
*/
int (*read_packet)(struct AVFormatContext *, AVPacket *pkt);
/**
* Close the stream. The AVFormatContext and AVStreams are not
* freed by this function
*/
int (*read_close)(struct AVFormatContext *);
/**
* Seek to a given timestamp relative to the frames in
* stream component stream_index.
* @param stream_index Must not be -1.
* @param flags Selects which direction should be preferred if no exact
* match is available.
* @return >= 0 on success (but not necessarily the new offset)
*/
int (*read_seek)(struct AVFormatContext *,
int stream_index, int64_t timestamp, int flags);
/**
* Get the next timestamp in stream[stream_index].time_base units.
* @return the timestamp or AV_NOPTS_VALUE if an error occurred
*/
int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index,
int64_t *pos, int64_t pos_limit);
/**
* Start/resume playing - only meaningful if using a network-based format
* (RTSP).
*/
int (*read_play)(struct AVFormatContext *);
/**
* Pause playing - only meaningful if using a network-based format
* (RTSP).
*/
int (*read_pause)(struct AVFormatContext *);
/**
* Seek to timestamp ts.
* Seeking will be done so that the point from which all active streams
* can be presented successfully will be closest to ts and within min/max_ts.
* Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
*/
int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
/**
* Returns device list with it properties.
* @see avdevice_list_devices() for more details.
*/
int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
/**
* Initialize device capabilities submodule.
* @see avdevice_capabilities_create() for more details.
*/
int (*create_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
/**
* Free device capabilities submodule.
* @see avdevice_capabilities_free() for more details.
*/
int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
} AVInputFormat;
3. demuxer_list的定义位于libavformat/demuxer_list.c
static const AVInputFormat * const demuxer_list[] = {
&ff_aa_demuxer,
&ff_aac_demuxer,
&ff_ac3_demuxer,
&ff_acm_demuxer,
&ff_act_demuxer,
&ff_adf_demuxer,
&ff_adp_demuxer,
&ff_ads_demuxer,
&ff_adx_demuxer,
&ff_aea_demuxer,
&ff_afc_demuxer,
&ff_aiff_demuxer,
&ff_aix_demuxer,
&ff_amr_demuxer,
&ff_amrnb_demuxer,
&ff_amrwb_demuxer,
&ff_anm_demuxer,
&ff_apc_demuxer,
&ff_ape_demuxer,
&ff_apng_demuxer,
&ff_aptx_demuxer,
&ff_aptx_hd_demuxer,
&ff_aqtitle_demuxer,
&ff_asf_demuxer,
&ff_asf_o_demuxer,
&ff_ass_demuxer,
&ff_ast_demuxer,
&ff_au_demuxer,
&ff_avi_demuxer,
&ff_avr_demuxer,
&ff_avs_demuxer,
&ff_avs2_demuxer,
&ff_bethsoftvid_demuxer,
&ff_bfi_demuxer,
&ff_bintext_demuxer,
&ff_bink_demuxer,
&ff_bit_demuxer,
&ff_bmv_demuxer,
&ff_bfstm_demuxer,
&ff_brstm_demuxer,
&ff_boa_demuxer,
&ff_c93_demuxer,
&ff_caf_demuxer,
&ff_cavsvideo_demuxer,
&ff_cdg_demuxer,
&ff_cdxl_demuxer,
&ff_cine_demuxer,
&ff_codec2_demuxer,
&ff_codec2raw_demuxer,
&ff_concat_demuxer,
&ff_data_demuxer,
&ff_daud_demuxer,
&ff_dcstr_demuxer,
&ff_dfa_demuxer,
&ff_dhav_demuxer,
&ff_dirac_demuxer,
&ff_dnxhd_demuxer,
&ff_dsf_demuxer,
&ff_dsicin_demuxer,
&ff_dss_demuxer,
&ff_dts_demuxer,
&ff_dtshd_demuxer,
&ff_dv_demuxer,
&ff_dvbsub_demuxer,
&ff_dvbtxt_demuxer,
&ff_dxa_demuxer,
&ff_ea_demuxer,
&ff_ea_cdata_demuxer,
&ff_eac3_demuxer,
&ff_epaf_demuxer,
&ff_ffmetadata_demuxer,
&ff_filmstrip_demuxer,
&ff_fits_demuxer,
&ff_flac_demuxer,
&ff_flic_demuxer,
&ff_flv_demuxer,
&ff_live_flv_demuxer,
&ff_fourxm_demuxer,
&ff_frm_demuxer,
&ff_fsb_demuxer,
&ff_g722_demuxer,
&ff_g723_1_demuxer,
&ff_g726_demuxer,
&ff_g726le_demuxer,
&ff_g729_demuxer,
&ff_gdv_demuxer,
&ff_genh_demuxer,
&ff_gif_demuxer,
&ff_gsm_demuxer,
&ff_gxf_demuxer,
&ff_h261_demuxer,
&ff_h263_demuxer,
&ff_h264_demuxer,
&ff_hcom_demuxer,
&ff_hevc_demuxer,
&ff_hls_demuxer,
&ff_hnm_demuxer,
&ff_ico_demuxer,
&ff_idcin_demuxer,
&ff_idf_demuxer,
&ff_iff_demuxer,
&ff_ifv_demuxer,
&ff_ilbc_demuxer,
&ff_image2_demuxer,
&ff_image2pipe_demuxer,
&ff_image2_alias_pix_demuxer,
&ff_image2_brender_pix_demuxer,
&ff_ingenient_demuxer,
&ff_ipmovie_demuxer,
&ff_ircam_demuxer,
&ff_iss_demuxer,
&ff_iv8_demuxer,
&ff_ivf_demuxer,
&ff_ivr_demuxer,
&ff_jacosub_demuxer,
&ff_jv_demuxer,
&ff_kux_demuxer,
&ff_lmlm4_demuxer,
&ff_loas_demuxer,
&ff_lrc_demuxer,
&ff_lvf_demuxer,
&ff_lxf_demuxer,
&ff_m4v_demuxer,
&ff_matroska_demuxer,
&ff_mgsts_demuxer,
&ff_microdvd_demuxer,
&ff_mjpeg_demuxer,
&ff_mjpeg_2000_demuxer,
&ff_mlp_demuxer,
&ff_mlv_demuxer,
&ff_mm_demuxer,
&ff_mmf_demuxer,
&ff_mov_demuxer,
&ff_mp3_demuxer,
&ff_mpc_demuxer,
&ff_mpc8_demuxer,
&ff_mpegps_demuxer,
&ff_mpegts_demuxer,
&ff_mpegtsraw_demuxer,
&ff_mpegvideo_demuxer,
&ff_mpjpeg_demuxer,
&ff_mpl2_demuxer,
&ff_mpsub_demuxer,
&ff_msf_demuxer,
&ff_msnwc_tcp_demuxer,
&ff_mtaf_demuxer,
&ff_mtv_demuxer,
&ff_musx_demuxer,
&ff_mv_demuxer,
&ff_mvi_demuxer,
&ff_mxf_demuxer,
&ff_mxg_demuxer,
&ff_nc_demuxer,
&ff_nistsphere_demuxer,
&ff_nsp_demuxer,
&ff_nsv_demuxer,
&ff_nut_demuxer,
&ff_nuv_demuxer,
&ff_ogg_demuxer,
&ff_oma_demuxer,
&ff_paf_demuxer,
&ff_pcm_alaw_demuxer,
&ff_pcm_mulaw_demuxer,
&ff_pcm_vidc_demuxer,
&ff_pcm_f64be_demuxer,
&ff_pcm_f64le_demuxer,
&ff_pcm_f32be_demuxer,
&ff_pcm_f32le_demuxer,
&ff_pcm_s32be_demuxer,
&ff_pcm_s32le_demuxer,
&ff_pcm_s24be_demuxer,
&ff_pcm_s24le_demuxer,
&ff_pcm_s16be_demuxer,
&ff_pcm_s16le_demuxer,
&ff_pcm_s8_demuxer,
&ff_pcm_u32be_demuxer,
&ff_pcm_u32le_demuxer,
&ff_pcm_u24be_demuxer,
&ff_pcm_u24le_demuxer,
&ff_pcm_u16be_demuxer,
&ff_pcm_u16le_demuxer,
&ff_pcm_u8_demuxer,
&ff_pjs_demuxer,
&ff_pmp_demuxer,
&ff_pva_demuxer,
&ff_pvf_demuxer,
&ff_qcp_demuxer,
&ff_r3d_demuxer,
&ff_rawvideo_demuxer,
&ff_realtext_demuxer,
&ff_redspark_demuxer,
&ff_rl2_demuxer,
&ff_rm_demuxer,
&ff_roq_demuxer,
&ff_rpl_demuxer,
&ff_rsd_demuxer,
&ff_rso_demuxer,
&ff_rtp_demuxer,
&ff_rtsp_demuxer,
&ff_s337m_demuxer,
&ff_sami_demuxer,
&ff_sap_demuxer,
&ff_sbc_demuxer,
&ff_sbg_demuxer,
&ff_scc_demuxer,
&ff_sdp_demuxer,
&ff_sdr2_demuxer,
&ff_sds_demuxer,
&ff_sdx_demuxer,
&ff_segafilm_demuxer,
&ff_ser_demuxer,
&ff_shorten_demuxer,
&ff_siff_demuxer,
&ff_sln_demuxer,
&ff_smacker_demuxer,
&ff_smjpeg_demuxer,
&ff_smush_demuxer,
&ff_sol_demuxer,
&ff_sox_demuxer,
&ff_spdif_demuxer,
&ff_srt_demuxer,
&ff_str_demuxer,
&ff_stl_demuxer,
&ff_subviewer1_demuxer,
&ff_subviewer_demuxer,
&ff_sup_demuxer,
&ff_svag_demuxer,
&ff_swf_demuxer,
&ff_tak_demuxer,
&ff_tedcaptions_demuxer,
&ff_thp_demuxer,
&ff_threedostr_demuxer,
&ff_tiertexseq_demuxer,
&ff_tmv_demuxer,
&ff_truehd_demuxer,
&ff_tta_demuxer,
&ff_txd_demuxer,
&ff_tty_demuxer,
&ff_ty_demuxer,
&ff_v210_demuxer,
&ff_v210x_demuxer,
&ff_vag_demuxer,
&ff_vc1_demuxer,
&ff_vc1t_demuxer,
&ff_vividas_demuxer,
&ff_vivo_demuxer,
&ff_vmd_demuxer,
&ff_vobsub_demuxer,
&ff_voc_demuxer,
&ff_vpk_demuxer,
&ff_vplayer_demuxer,
&ff_vqf_demuxer,
&ff_w64_demuxer,
&ff_wav_demuxer,
&ff_wc3_demuxer,
&ff_webm_dash_manifest_demuxer,
&ff_webvtt_demuxer,
&ff_wsaud_demuxer,
&ff_wsd_demuxer,
&ff_wsvqa_demuxer,
&ff_wtv_demuxer,
&ff_wve_demuxer,
&ff_wv_demuxer,
&ff_xa_demuxer,
&ff_xbin_demuxer,
&ff_xmv_demuxer,
&ff_xvag_demuxer,
&ff_xwma_demuxer,
&ff_yop_demuxer,
&ff_yuv4mpegpipe_demuxer,
&ff_image_bmp_pipe_demuxer,
&ff_image_dds_pipe_demuxer,
&ff_image_dpx_pipe_demuxer,
&ff_image_exr_pipe_demuxer,
&ff_image_gif_pipe_demuxer,
&ff_image_j2k_pipe_demuxer,
&ff_image_jpeg_pipe_demuxer,
&ff_image_jpegls_pipe_demuxer,
&ff_image_pam_pipe_demuxer,
&ff_image_pbm_pipe_demuxer,
&ff_image_pcx_pipe_demuxer,
&ff_image_pgmyuv_pipe_demuxer,
&ff_image_pgm_pipe_demuxer,
&ff_image_pictor_pipe_demuxer,
&ff_image_png_pipe_demuxer,
&ff_image_ppm_pipe_demuxer,
&ff_image_psd_pipe_demuxer,
&ff_image_qdraw_pipe_demuxer,
&ff_image_sgi_pipe_demuxer,
&ff_image_svg_pipe_demuxer,
&ff_image_sunrast_pipe_demuxer,
&ff_image_tiff_pipe_demuxer,
&ff_image_webp_pipe_demuxer,
&ff_image_xpm_pipe_demuxer,
&ff_image_xwd_pipe_demuxer,
NULL };
// 举例说明
AVInputFormat ff_aac_demuxer = {
.name = "aac",
.long_name = NULL_IF_CONFIG_SMALL("raw ADTS AAC (Advanced Audio Coding)"),
.read_probe = adts_aac_probe,
.read_header = adts_aac_read_header,
.read_packet = adts_aac_read_packet,
.flags = AVFMT_GENERIC_INDEX,
.extensions = "aac",
.mime_type = "audio/aac,audio/aacp,audio/x-aac",
.raw_codec_id = AV_CODEC_ID_AAC,
};
4.. indev_list的定义位于libavdevice/indev_list.c
static const AVInputFormat * const indev_list[] = {
&ff_alsa_demuxer,
&ff_fbdev_demuxer,
&ff_lavfi_demuxer,
&ff_oss_demuxer,
&ff_sndio_demuxer,
&ff_v4l2_demuxer,
&ff_xcbgrab_demuxer,
NULL
};
// 举例说明
AVInputFormat ff_lavfi_demuxer = {
.name = "lavfi",
.long_name = NULL_IF_CONFIG_SMALL("Libavfilter virtual input device"),
.priv_data_size = sizeof(LavfiContext),
.read_header = lavfi_read_header,
.read_packet = lavfi_read_packet,
.read_close = lavfi_read_close,
.flags = AVFMT_NOFILE,
.priv_class = &lavfi_class,
};
AVOutputFormat
1. AVOutputFormat是muxer或者outdev
AVOutputFormat *prevout = NULL, *out;
for (int i = 0; (out = (AVOutputFormat*)muxer_list[i]); i++) {
if (prevout)
prevout->next = out;
prevout = out;
}
if (outdev_list) {
for (int i = 0; (out = (AVOutputFormat*)outdev_list[i]); i++) {
if (prevout)
prevout->next = out;
prevout = out;
}
}
2. AVOutputFormat的声明
typedef struct AVOutputFormat {
const char *name;
/**
* Descriptive name for the format, meant to be more human-readable
* than name. You should use the NULL_IF_CONFIG_SMALL() macro
* to define it.
*/
const char *long_name;
const char *mime_type;
const char *extensions; /**< comma-separated filename extensions */
/* output support */
enum AVCodecID audio_codec; /**< default audio codec */
enum AVCodecID video_codec; /**< default video codec */
enum AVCodecID subtitle_codec; /**< default subtitle codec */
/**
* can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER,
* AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS,
* AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS, AVFMT_ALLOW_FLUSH,
* AVFMT_TS_NONSTRICT, AVFMT_TS_NEGATIVE
*/
int flags;
/**
* List of supported codec_id-codec_tag pairs, ordered by "better
* choice first". The arrays are all terminated by AV_CODEC_ID_NONE.
*/
const struct AVCodecTag * const *codec_tag;
const AVClass *priv_class; ///< AVClass for the private context
/*****************************************************************
* No fields below this line are part of the public API. They
* may not be used outside of libavformat and can be changed and
* removed at will.
* New public fields should be added right above.
*****************************************************************
*/
/**
* The ff_const59 define is not part of the public API and will
* be removed without further warning.
*/
#if FF_API_AVIOFORMAT
#define ff_const59
#else
#define ff_const59 const
#endif
ff_const59 struct AVOutputFormat *next;
/**
* size of private data so that it can be allocated in the wrapper
*/
int priv_data_size;
int (*write_header)(struct AVFormatContext *);
/**
* Write a packet. If AVFMT_ALLOW_FLUSH is set in flags,
* pkt can be NULL in order to flush data buffered in the muxer.
* When flushing, return 0 if there still is more data to flush,
* or 1 if everything was flushed and there is no more buffered
* data.
*/
int (*write_packet)(struct AVFormatContext *, AVPacket *pkt);
int (*write_trailer)(struct AVFormatContext *);
/**
* Currently only used to set pixel format if not YUV420P.
*/
int (*interleave_packet)(struct AVFormatContext *, AVPacket *out,
AVPacket *in, int flush);
/**
* Test if the given codec can be stored in this container.
*
* @return 1 if the codec is supported, 0 if it is not.
* A negative number if unknown.
* MKTAG('A', 'P', 'I', 'C') if the codec is only supported as AV_DISPOSITION_ATTACHED_PIC
*/
int (*query_codec)(enum AVCodecID id, int std_compliance);
void (*get_output_timestamp)(struct AVFormatContext *s, int stream,
int64_t *dts, int64_t *wall);
/**
* Allows sending messages from application to device.
*/
int (*control_message)(struct AVFormatContext *s, int type,
void *data, size_t data_size);
/**
* Write an uncoded AVFrame.
*
* See av_write_uncoded_frame() for details.
*
* The library will free *frame afterwards, but the muxer can prevent it
* by setting the pointer to NULL.
*/
int (*write_uncoded_frame)(struct AVFormatContext *, int stream_index,
AVFrame **frame, unsigned flags);
/**
* Returns device list with it properties.
* @see avdevice_list_devices() for more details.
*/
int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
/**
* Initialize device capabilities submodule.
* @see avdevice_capabilities_create() for more details.
*/
int (*create_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
/**
* Free device capabilities submodule.
* @see avdevice_capabilities_free() for more details.
*/
int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
enum AVCodecID data_codec; /**< default data codec */
/**
* Initialize format. May allocate data here, and set any AVFormatContext or
* AVStream parameters that need to be set before packets are sent.
* This method must not write output.
*
* Return 0 if streams were fully configured, 1 if not, negative AVERROR on failure
*
* Any allocations made here must be freed in deinit().
*/
int (*init)(struct AVFormatContext *);
/**
* Deinitialize format. If present, this is called whenever the muxer is being
* destroyed, regardless of whether or not the header has been written.
*
* If a trailer is being written, this is called after write_trailer().
*
* This is called if init() fails as well.
*/
void (*deinit)(struct AVFormatContext *);
/**
* Set up any necessary bitstream filtering and extract any extra data needed
* for the global header.
* Return 0 if more packets from this stream must be checked; 1 if not.
*/
int (*check_bitstream)(struct AVFormatContext *, const AVPacket *pkt);
} AVOutputFormat;
3. muxer_list的定义位于libavformat/muxer_list.c
static const AVOutputFormat * const muxer_list[] = {
&ff_a64_muxer,
&ff_ac3_muxer,
&ff_adts_muxer,
&ff_adx_muxer,
&ff_aiff_muxer,
&ff_amr_muxer,
&ff_apng_muxer,
&ff_aptx_muxer,
&ff_aptx_hd_muxer,
&ff_asf_muxer,
&ff_ass_muxer,
&ff_ast_muxer,
&ff_asf_stream_muxer,
&ff_au_muxer,
&ff_avi_muxer,
&ff_avm2_muxer,
&ff_avs2_muxer,
&ff_bit_muxer,
&ff_caf_muxer,
&ff_cavsvideo_muxer,
&ff_codec2_muxer,
&ff_codec2raw_muxer,
&ff_crc_muxer,
&ff_dash_muxer,
&ff_data_muxer,
&ff_daud_muxer,
&ff_dirac_muxer,
&ff_dnxhd_muxer,
&ff_dts_muxer,
&ff_dv_muxer,
&ff_eac3_muxer,
&ff_f4v_muxer,
&ff_ffmetadata_muxer,
&ff_fifo_muxer,
&ff_fifo_test_muxer,
&ff_filmstrip_muxer,
&ff_fits_muxer,
&ff_flac_muxer,
&ff_flv_muxer,
&ff_framecrc_muxer,
&ff_framehash_muxer,
&ff_framemd5_muxer,
&ff_g722_muxer,
&ff_g723_1_muxer,
&ff_g726_muxer,
&ff_g726le_muxer,
&ff_gif_muxer,
&ff_gsm_muxer,
&ff_gxf_muxer,
&ff_h261_muxer,
&ff_h263_muxer,
&ff_h264_muxer,
&ff_hash_muxer,
&ff_hds_muxer,
&ff_hevc_muxer,
&ff_hls_muxer,
&ff_ico_muxer,
&ff_ilbc_muxer,
&ff_image2_muxer,
&ff_image2pipe_muxer,
&ff_ipod_muxer,
&ff_ircam_muxer,
&ff_ismv_muxer,
&ff_ivf_muxer,
&ff_jacosub_muxer,
&ff_latm_muxer,
&ff_lrc_muxer,
&ff_m4v_muxer,
&ff_md5_muxer,
&ff_matroska_muxer,
&ff_matroska_audio_muxer,
&ff_microdvd_muxer,
&ff_mjpeg_muxer,
&ff_mlp_muxer,
&ff_mmf_muxer,
&ff_mov_muxer,
&ff_mp2_muxer,
&ff_mp3_muxer,
&ff_mp4_muxer,
&ff_mpeg1system_muxer,
&ff_mpeg1vcd_muxer,
&ff_mpeg1video_muxer,
&ff_mpeg2dvd_muxer,
&ff_mpeg2svcd_muxer,
&ff_mpeg2video_muxer,
&ff_mpeg2vob_muxer,
&ff_mpegts_muxer,
&ff_mpjpeg_muxer,
&ff_mxf_muxer,
&ff_mxf_d10_muxer,
&ff_mxf_opatom_muxer,
&ff_null_muxer,
&ff_nut_muxer,
&ff_oga_muxer,
&ff_ogg_muxer,
&ff_ogv_muxer,
&ff_oma_muxer,
&ff_opus_muxer,
&ff_pcm_alaw_muxer,
&ff_pcm_mulaw_muxer,
&ff_pcm_vidc_muxer,
&ff_pcm_f64be_muxer,
&ff_pcm_f64le_muxer,
&ff_pcm_f32be_muxer,
&ff_pcm_f32le_muxer,
&ff_pcm_s32be_muxer,
&ff_pcm_s32le_muxer,
&ff_pcm_s24be_muxer,
&ff_pcm_s24le_muxer,
&ff_pcm_s16be_muxer,
&ff_pcm_s16le_muxer,
&ff_pcm_s8_muxer,
&ff_pcm_u32be_muxer,
&ff_pcm_u32le_muxer,
&ff_pcm_u24be_muxer,
&ff_pcm_u24le_muxer,
&ff_pcm_u16be_muxer,
&ff_pcm_u16le_muxer,
&ff_pcm_u8_muxer,
&ff_psp_muxer,
&ff_rawvideo_muxer,
&ff_rm_muxer,
&ff_roq_muxer,
&ff_rso_muxer,
&ff_rtp_muxer,
&ff_rtp_mpegts_muxer,
&ff_rtsp_muxer,
&ff_sap_muxer,
&ff_sbc_muxer,
&ff_scc_muxer,
&ff_segafilm_muxer,
&ff_segment_muxer,
&ff_stream_segment_muxer,
&ff_singlejpeg_muxer,
&ff_smjpeg_muxer,
&ff_smoothstreaming_muxer,
&ff_sox_muxer,
&ff_spx_muxer,
&ff_spdif_muxer,
&ff_srt_muxer,
&ff_sup_muxer,
&ff_swf_muxer,
&ff_tee_muxer,
&ff_tg2_muxer,
&ff_tgp_muxer,
&ff_mkvtimestamp_v2_muxer,
&ff_truehd_muxer,
&ff_tta_muxer,
&ff_uncodedframecrc_muxer,
&ff_vc1_muxer,
&ff_vc1t_muxer,
&ff_voc_muxer,
&ff_w64_muxer,
&ff_wav_muxer,
&ff_webm_muxer,
&ff_webm_dash_manifest_muxer,
&ff_webm_chunk_muxer,
&ff_webp_muxer,
&ff_webvtt_muxer,
&ff_wtv_muxer,
&ff_wv_muxer,
&ff_yuv4mpegpipe_muxer,
NULL };
// 举例说明
AVOutputFormat ff_h264_muxer = {
.name = "h264",
.long_name = NULL_IF_CONFIG_SMALL("raw H.264 video"),
.extensions = "h264,264",
.audio_codec = AV_CODEC_ID_NONE,
.video_codec = AV_CODEC_ID_H264,
.write_header = force_one_stream,
.write_packet = ff_raw_write_packet,
.check_bitstream = h264_check_bitstream,
.flags = AVFMT_NOTIMESTAMPS,
};
4. outdev_list的定义位于libavdevice/outdev_list.c
static const AVOutputFormat * const outdev_list[] = {
&ff_alsa_muxer,
&ff_fbdev_muxer,
&ff_oss_muxer,
&ff_sdl2_muxer,
&ff_sndio_muxer,
&ff_v4l2_muxer,
&ff_xv_muxer,
NULL
};
AVOutputFormat ff_sdl2_muxer = {
.name = "sdl,sdl2",
.long_name = NULL_IF_CONFIG_SMALL("SDL2 output device"),
.priv_data_size = sizeof(SDLContext),
.audio_codec = AV_CODEC_ID_NONE,
.video_codec = AV_CODEC_ID_RAWVIDEO,
.write_header = sdl2_write_header,
.write_packet = sdl2_write_packet,
.write_trailer = sdl2_write_trailer,
.flags = AVFMT_NOFILE | AVFMT_VARIABLE_FPS | AVFMT_NOTIMESTAMPS,
.priv_class = &sdl2_class,
};
结论
AVInputFormat可以理解为demuxer, AVOutputFormat可以理解为muxer