FFmpeg
null.c
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1 /*
2  * Null codecs
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include "config_components.h"
22 
23 #include "codec_internal.h"
24 #include "decode.h"
25 #include "encode.h"
26 
27 #if CONFIG_VNULL_DECODER || CONFIG_ANULL_DECODER
28 static int null_decode(AVCodecContext *avctx, AVFrame *frame,
29  int *got_frame, AVPacket *avpkt)
30 {
31  *got_frame = 0;
32  return avpkt->size;
33 }
34 
35 #if CONFIG_VNULL_DECODER
36 const FFCodec ff_vnull_decoder = {
37  .p.name = "vnull",
38  CODEC_LONG_NAME("null video"),
39  .p.type = AVMEDIA_TYPE_VIDEO,
40  .p.id = AV_CODEC_ID_VNULL,
41  .p.capabilities = AV_CODEC_CAP_DR1,
42  FF_CODEC_DECODE_CB(null_decode),
43 };
44 #endif
45 
46 #if CONFIG_ANULL_DECODER
47 const FFCodec ff_anull_decoder = {
48  .p.name = "anull",
49  CODEC_LONG_NAME("null audio"),
50  .p.type = AVMEDIA_TYPE_AUDIO,
51  .p.id = AV_CODEC_ID_ANULL,
52  .p.capabilities = AV_CODEC_CAP_DR1,
53  FF_CODEC_DECODE_CB(null_decode),
54 };
55 #endif
56 
57 #endif
58 
59 #if CONFIG_VNULL_ENCODER || CONFIG_ANULL_ENCODER
60 static int null_encode(AVCodecContext *avctx, AVPacket *pkt,
61  const AVFrame *frame, int *got_packet)
62 {
63  *got_packet = 0;
64  return 0;
65 }
66 
67 #if CONFIG_VNULL_ENCODER
68 const FFCodec ff_vnull_encoder = {
69  .p.name = "vnull",
70  CODEC_LONG_NAME("null video"),
71  .p.type = AVMEDIA_TYPE_VIDEO,
72  .p.id = AV_CODEC_ID_VNULL,
73  FF_CODEC_ENCODE_CB(null_encode),
74 };
75 #endif
76 
77 #if CONFIG_ANULL_ENCODER
78 const FFCodec ff_anull_encoder = {
79  .p.name = "anull",
80  CODEC_LONG_NAME("null audio"),
81  .p.type = AVMEDIA_TYPE_AUDIO,
82  .p.id = AV_CODEC_ID_ANULL,
83  .p.capabilities = AV_CODEC_CAP_VARIABLE_FRAME_SIZE,
84  .p.sample_fmts = (const enum AVSampleFormat[]){
92  },
93  FF_CODEC_ENCODE_CB(null_encode),
94 };
95 #endif
96 
97 #endif
AV_SAMPLE_FMT_FLTP
@ AV_SAMPLE_FMT_FLTP
float, planar
Definition: samplefmt.h:66
ff_vnull_decoder
const FFCodec ff_vnull_decoder
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:389
encode.h
AV_SAMPLE_FMT_S32P
@ AV_SAMPLE_FMT_S32P
signed 32 bits, planar
Definition: samplefmt.h:65
FFCodec
Definition: codec_internal.h:127
AV_CODEC_ID_VNULL
@ AV_CODEC_ID_VNULL
Dummy null video codec, useful mainly for development and debugging.
Definition: codec_id.h:613
FFCodec::p
AVCodec p
The public AVCodec.
Definition: codec_internal.h:131
ff_anull_encoder
const FFCodec ff_anull_encoder
AV_SAMPLE_FMT_S64P
@ AV_SAMPLE_FMT_S64P
signed 64 bits, planar
Definition: samplefmt.h:69
FF_CODEC_ENCODE_CB
#define FF_CODEC_ENCODE_CB(func)
Definition: codec_internal.h:320
pkt
AVPacket * pkt
Definition: movenc.c:60
FF_CODEC_DECODE_CB
#define FF_CODEC_DECODE_CB(func)
Definition: codec_internal.h:311
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
decode.h
CODEC_LONG_NAME
#define CODEC_LONG_NAME(str)
Definition: codec_internal.h:296
ff_vnull_encoder
const FFCodec ff_vnull_encoder
AV_CODEC_CAP_VARIABLE_FRAME_SIZE
#define AV_CODEC_CAP_VARIABLE_FRAME_SIZE
Audio encoder supports receiving a different number of samples in each call.
Definition: codec.h:128
AV_CODEC_CAP_DR1
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:52
AVPacket::size
int size
Definition: packet.h:540
AV_SAMPLE_FMT_U8P
@ AV_SAMPLE_FMT_U8P
unsigned 8 bits, planar
Definition: samplefmt.h:63
codec_internal.h
AV_CODEC_ID_ANULL
@ AV_CODEC_ID_ANULL
Dummy null audio codec, useful mainly for development and debugging.
Definition: codec_id.h:618
AV_SAMPLE_FMT_NONE
@ AV_SAMPLE_FMT_NONE
Definition: samplefmt.h:56
AV_SAMPLE_FMT_S16P
@ AV_SAMPLE_FMT_S16P
signed 16 bits, planar
Definition: samplefmt.h:64
AV_SAMPLE_FMT_U8
@ AV_SAMPLE_FMT_U8
unsigned 8 bits
Definition: samplefmt.h:57
AVSampleFormat
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:55
AV_SAMPLE_FMT_S16
@ AV_SAMPLE_FMT_S16
signed 16 bits
Definition: samplefmt.h:58
ff_anull_decoder
const FFCodec ff_anull_decoder
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:194
frame
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
Definition: filter_design.txt:264
AVCodecContext
main external API structure.
Definition: avcodec.h:451
AV_SAMPLE_FMT_DBLP
@ AV_SAMPLE_FMT_DBLP
double, planar
Definition: samplefmt.h:67
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
AVPacket
This structure stores compressed data.
Definition: packet.h:516
AV_SAMPLE_FMT_DBL
@ AV_SAMPLE_FMT_DBL
double
Definition: samplefmt.h:61
AV_SAMPLE_FMT_S32
@ AV_SAMPLE_FMT_S32
signed 32 bits
Definition: samplefmt.h:59
AV_SAMPLE_FMT_FLT
@ AV_SAMPLE_FMT_FLT
float
Definition: samplefmt.h:60
AV_SAMPLE_FMT_S64
@ AV_SAMPLE_FMT_S64
signed 64 bits
Definition: samplefmt.h:68