FFmpeg
pcm_rechunk_bsf.c
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1 /*
2  * Copyright (c) 2020 Marton Balint
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 "bsf.h"
22 #include "bsf_internal.h"
23 #include "libavutil/avassert.h"
24 #include "libavutil/opt.h"
25 
26 typedef struct PCMContext {
27  const AVClass *class;
28 
30  int pad;
32 
36  int64_t n;
37 } PCMContext;
38 
39 static int init(AVBSFContext *ctx)
40 {
42  AVRational sr = av_make_q(ctx->par_in->sample_rate, 1);
43  int64_t min_samples;
44 
45  if (ctx->par_in->channels <= 0 || ctx->par_in->sample_rate <= 0)
46  return AVERROR(EINVAL);
47 
48  ctx->time_base_out = av_inv_q(sr);
49  s->sample_size = ctx->par_in->channels * av_get_bits_per_sample(ctx->par_in->codec_id) / 8;
50 
51  if (s->frame_rate.num) {
52  min_samples = av_rescale_q_rnd(1, sr, s->frame_rate, AV_ROUND_DOWN);
53  } else {
54  min_samples = s->nb_out_samples;
55  }
56  if (min_samples <= 0 || min_samples > INT_MAX / s->sample_size - 1)
57  return AVERROR(EINVAL);
58 
59  s->in_pkt = av_packet_alloc();
60  s->out_pkt = av_packet_alloc();
61  if (!s->in_pkt || !s->out_pkt)
62  return AVERROR(ENOMEM);
63 
64  return 0;
65 }
66 
67 static void uninit(AVBSFContext *ctx)
68 {
70  av_packet_free(&s->in_pkt);
71  av_packet_free(&s->out_pkt);
72 }
73 
74 static void flush(AVBSFContext *ctx)
75 {
77  av_packet_unref(s->in_pkt);
78  av_packet_unref(s->out_pkt);
79  s->n = 0;
80 }
81 
82 static int send_packet(PCMContext *s, int nb_samples, AVPacket *pkt)
83 {
84  pkt->duration = nb_samples;
85  s->n++;
86  return 0;
87 }
88 
89 static void drain_packet(AVPacket *pkt, int drain_data, int drain_samples)
90 {
91  pkt->size -= drain_data;
92  pkt->data += drain_data;
93  if (pkt->dts != AV_NOPTS_VALUE)
94  pkt->dts += drain_samples;
95  if (pkt->pts != AV_NOPTS_VALUE)
96  pkt->pts += drain_samples;
97 }
98 
100 {
102  if (s->frame_rate.num) {
103  AVRational sr = av_make_q(ctx->par_in->sample_rate, 1);
104  return av_rescale_q(s->n + 1, sr, s->frame_rate) - av_rescale_q(s->n, sr, s->frame_rate);
105  } else {
106  return s->nb_out_samples;
107  }
108 }
109 
111 {
113  int nb_samples = get_next_nb_samples(ctx);
114  int data_size = nb_samples * s->sample_size;
115  int ret;
116 
117  do {
118  if (s->in_pkt->size) {
119  if (s->out_pkt->size || s->in_pkt->size < data_size) {
120  int drain = FFMIN(s->in_pkt->size, data_size - s->out_pkt->size);
121  if (!s->out_pkt->size) {
122  ret = av_new_packet(s->out_pkt, data_size);
123  if (ret < 0)
124  return ret;
125  ret = av_packet_copy_props(s->out_pkt, s->in_pkt);
126  if (ret < 0) {
127  av_packet_unref(s->out_pkt);
128  return ret;
129  }
130  s->out_pkt->size = 0;
131  }
132  memcpy(s->out_pkt->data + s->out_pkt->size, s->in_pkt->data, drain);
133  s->out_pkt->size += drain;
134  drain_packet(s->in_pkt, drain, drain / s->sample_size);
135  if (!s->in_pkt->size)
136  av_packet_unref(s->in_pkt);
137  if (s->out_pkt->size == data_size) {
138  av_packet_move_ref(pkt, s->out_pkt);
139  return send_packet(s, nb_samples, pkt);
140  }
141  } else if (s->in_pkt->size > data_size) {
142  ret = av_packet_ref(pkt, s->in_pkt);
143  if (ret < 0)
144  return ret;
145  pkt->size = data_size;
146  drain_packet(s->in_pkt, data_size, nb_samples);
147  return send_packet(s, nb_samples, pkt);
148  } else {
149  av_assert0(s->in_pkt->size == data_size);
150  av_packet_move_ref(pkt, s->in_pkt);
151  return send_packet(s, nb_samples, pkt);
152  }
153  }
154 
155  ret = ff_bsf_get_packet_ref(ctx, s->in_pkt);
156  if (ret == AVERROR_EOF && s->out_pkt->size) {
157  if (s->pad) {
158  memset(s->out_pkt->data + s->out_pkt->size, 0, data_size - s->out_pkt->size);
159  s->out_pkt->size = data_size;
160  } else {
161  nb_samples = s->out_pkt->size / s->sample_size;
162  }
163  av_packet_move_ref(pkt, s->out_pkt);
164  return send_packet(s, nb_samples, pkt);
165  }
166  if (ret >= 0)
167  av_packet_rescale_ts(s->in_pkt, ctx->time_base_in, ctx->time_base_out);
168  } while (ret >= 0);
169 
170  return ret;
171 }
172 
173 #define OFFSET(x) offsetof(PCMContext, x)
174 #define FLAGS (AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_BSF_PARAM)
175 static const AVOption options[] = {
176  { "nb_out_samples", "set the number of per-packet output samples", OFFSET(nb_out_samples), AV_OPT_TYPE_INT, {.i64=1024}, 1, INT_MAX, FLAGS },
177  { "n", "set the number of per-packet output samples", OFFSET(nb_out_samples), AV_OPT_TYPE_INT, {.i64=1024}, 1, INT_MAX, FLAGS },
178  { "pad", "pad last packet with zeros", OFFSET(pad), AV_OPT_TYPE_BOOL, {.i64=1} , 0, 1, FLAGS },
179  { "p", "pad last packet with zeros", OFFSET(pad), AV_OPT_TYPE_BOOL, {.i64=1} , 0, 1, FLAGS },
180  { "frame_rate", "set number of packets per second", OFFSET(frame_rate), AV_OPT_TYPE_RATIONAL, {.dbl=0}, 0, INT_MAX, FLAGS },
181  { "r", "set number of packets per second", OFFSET(frame_rate), AV_OPT_TYPE_RATIONAL, {.dbl=0}, 0, INT_MAX, FLAGS },
182  { NULL },
183 };
184 
185 static const AVClass pcm_rechunk_class = {
186  .class_name = "pcm_rechunk_bsf",
187  .item_name = av_default_item_name,
188  .option = options,
189  .version = LIBAVUTIL_VERSION_INT,
190 };
191 
192 static const enum AVCodecID codec_ids[] = {
209 };
210 
212  .name = "pcm_rechunk",
213  .priv_data_size = sizeof(PCMContext),
214  .priv_class = &pcm_rechunk_class,
216  .init = init,
217  .flush = flush,
218  .close = uninit,
219  .codec_ids = codec_ids,
220 };
AV_CODEC_ID_PCM_S16LE
@ AV_CODEC_ID_PCM_S16LE
Definition: codec_id.h:314
av_packet_unref
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:417
PCMContext::nb_out_samples
int nb_out_samples
Definition: pcm_rechunk_bsf.c:29
AV_CODEC_ID_PCM_F32BE
@ AV_CODEC_ID_PCM_F32BE
Definition: codec_id.h:334
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
opt.h
bsf_internal.h
AVERROR_EOF
#define AVERROR_EOF
End of file.
Definition: error.h:57
AVBitStreamFilter::name
const char * name
Definition: bsf.h:91
AVPacket::data
uint8_t * data
Definition: packet.h:373
uninit
static void uninit(AVBSFContext *ctx)
Definition: pcm_rechunk_bsf.c:67
AVOption
AVOption.
Definition: opt.h:247
AVPacket::duration
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: packet.h:391
PCMContext::sample_size
int sample_size
Definition: pcm_rechunk_bsf.c:35
filter
filter_frame For filters that do not use the this method is called when a frame is pushed to the filter s input It can be called at any time except in a reentrant way If the input frame is enough to produce then the filter should push the output frames on the output link immediately As an exception to the previous rule if the input frame is enough to produce several output frames then the filter needs output only at least one per link The additional frames can be left buffered in the filter
Definition: filter_design.txt:228
AV_OPT_TYPE_RATIONAL
@ AV_OPT_TYPE_RATIONAL
Definition: opt.h:229
av_packet_free
void av_packet_free(AVPacket **pkt)
Free the packet, if the packet is reference counted, it will be unreferenced first.
Definition: avpacket.c:75
AVBSFContext
The bitstream filter state.
Definition: bsf.h:47
AV_CODEC_ID_PCM_S64LE
@ AV_CODEC_ID_PCM_S64LE
Definition: codec_id.h:345
FLAGS
#define FLAGS
Definition: pcm_rechunk_bsf.c:174
bsf.h
AV_CODEC_ID_PCM_S16BE
@ AV_CODEC_ID_PCM_S16BE
Definition: codec_id.h:315
rechunk_filter
static int rechunk_filter(AVBSFContext *ctx, AVPacket *pkt)
Definition: pcm_rechunk_bsf.c:110
OFFSET
#define OFFSET(x)
Definition: pcm_rechunk_bsf.c:173
av_get_bits_per_sample
int av_get_bits_per_sample(enum AVCodecID codec_id)
Return codec bits per sample.
Definition: utils.c:591
flush
static void flush(AVBSFContext *ctx)
Definition: pcm_rechunk_bsf.c:74
ff_pcm_rechunk_bsf
const AVBitStreamFilter ff_pcm_rechunk_bsf
Definition: pcm_rechunk_bsf.c:211
AV_CODEC_ID_PCM_S8
@ AV_CODEC_ID_PCM_S8
Definition: codec_id.h:318
avassert.h
pkt
AVPacket * pkt
Definition: movenc.c:59
s
#define s(width, name)
Definition: cbs_vp9.c:257
av_new_packet
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:99
av_assert0
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
ctx
AVFormatContext * ctx
Definition: movenc.c:48
AV_CODEC_ID_PCM_F24LE
@ AV_CODEC_ID_PCM_F24LE
Definition: codec_id.h:348
av_rescale_q
int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq)
Rescale a 64-bit integer by 2 rational numbers.
Definition: mathematics.c:141
init
static int init(AVBSFContext *ctx)
Definition: pcm_rechunk_bsf.c:39
LIBAVUTIL_VERSION_INT
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
NULL
#define NULL
Definition: coverity.c:32
AVRational
Rational number (pair of numerator and denominator).
Definition: rational.h:58
av_default_item_name
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:235
AV_CODEC_ID_PCM_S64BE
@ AV_CODEC_ID_PCM_S64BE
Definition: codec_id.h:346
av_packet_ref
int av_packet_ref(AVPacket *dst, const AVPacket *src)
Setup a new reference to the data described by a given packet.
Definition: avpacket.c:425
av_packet_move_ref
void av_packet_move_ref(AVPacket *dst, AVPacket *src)
Move every field in src to dst and reset src.
Definition: avpacket.c:474
AVCodecID
AVCodecID
Identify the syntax and semantics of the bitstream.
Definition: codec_id.h:47
AV_CODEC_ID_PCM_S24LE
@ AV_CODEC_ID_PCM_S24LE
Definition: codec_id.h:326
PCMContext::in_pkt
AVPacket * in_pkt
Definition: pcm_rechunk_bsf.c:33
AVPacket::size
int size
Definition: packet.h:374
PCMContext::n
int64_t n
Definition: pcm_rechunk_bsf.c:36
PCMContext
Definition: pcm_rechunk_bsf.c:26
av_make_q
static AVRational av_make_q(int num, int den)
Create an AVRational.
Definition: rational.h:71
AV_NOPTS_VALUE
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:248
AVPacket::dts
int64_t dts
Decompression timestamp in AVStream->time_base units; the time at which the packet is decompressed.
Definition: packet.h:372
av_packet_alloc
AVPacket * av_packet_alloc(void)
Allocate an AVPacket and set its fields to default values.
Definition: avpacket.c:64
av_packet_rescale_ts
void av_packet_rescale_ts(AVPacket *pkt, AVRational src_tb, AVRational dst_tb)
Convert valid timing fields (timestamps / durations) in a packet from one timebase to another.
Definition: avpacket.c:521
av_packet_copy_props
int av_packet_copy_props(AVPacket *dst, const AVPacket *src)
Copy only "properties" fields from src to dst.
Definition: avpacket.c:380
AV_CODEC_ID_NONE
@ AV_CODEC_ID_NONE
Definition: codec_id.h:48
AVPacket::pts
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: packet.h:366
pcm_rechunk_class
static const AVClass pcm_rechunk_class
Definition: pcm_rechunk_bsf.c:185
AV_ROUND_DOWN
@ AV_ROUND_DOWN
Round toward -infinity.
Definition: mathematics.h:82
AV_CODEC_ID_PCM_F64BE
@ AV_CODEC_ID_PCM_F64BE
Definition: codec_id.h:336
FFMIN
#define FFMIN(a, b)
Definition: macros.h:49
AV_CODEC_ID_PCM_S32BE
@ AV_CODEC_ID_PCM_S32BE
Definition: codec_id.h:323
av_inv_q
static av_always_inline AVRational av_inv_q(AVRational q)
Invert a rational.
Definition: rational.h:159
AV_CODEC_ID_PCM_F16LE
@ AV_CODEC_ID_PCM_F16LE
Definition: codec_id.h:347
PCMContext::pad
int pad
Definition: pcm_rechunk_bsf.c:30
ret
ret
Definition: filter_design.txt:187
AVClass::class_name
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:71
codec_ids
static enum AVCodecID codec_ids[]
Definition: pcm_rechunk_bsf.c:192
AVBitStreamFilter
Definition: bsf.h:90
AV_OPT_TYPE_INT
@ AV_OPT_TYPE_INT
Definition: opt.h:224
send_packet
static int send_packet(PCMContext *s, int nb_samples, AVPacket *pkt)
Definition: pcm_rechunk_bsf.c:82
AV_CODEC_ID_PCM_S32LE
@ AV_CODEC_ID_PCM_S32LE
Definition: codec_id.h:322
options
static const AVOption options[]
Definition: pcm_rechunk_bsf.c:175
AV_CODEC_ID_PCM_F64LE
@ AV_CODEC_ID_PCM_F64LE
Definition: codec_id.h:337
AVPacket
This structure stores compressed data.
Definition: packet.h:350
AV_OPT_TYPE_BOOL
@ AV_OPT_TYPE_BOOL
Definition: opt.h:241
AV_CODEC_ID_PCM_F32LE
@ AV_CODEC_ID_PCM_F32LE
Definition: codec_id.h:335
ff_bsf_get_packet_ref
int ff_bsf_get_packet_ref(AVBSFContext *ctx, AVPacket *pkt)
Called by bitstream filters to get packet for filtering.
Definition: bsf.c:252
get_next_nb_samples
static int get_next_nb_samples(AVBSFContext *ctx)
Definition: pcm_rechunk_bsf.c:99
AVFormatContext::priv_data
void * priv_data
Format private data.
Definition: avformat.h:1221
AV_CODEC_ID_PCM_S24BE
@ AV_CODEC_ID_PCM_S24BE
Definition: codec_id.h:327
av_rescale_q_rnd
int64_t av_rescale_q_rnd(int64_t a, AVRational bq, AVRational cq, enum AVRounding rnd)
Rescale a 64-bit integer by 2 rational numbers with specified rounding.
Definition: mathematics.c:133
PCMContext::out_pkt
AVPacket * out_pkt
Definition: pcm_rechunk_bsf.c:34
PCMContext::frame_rate
AVRational frame_rate
Definition: pcm_rechunk_bsf.c:31
drain_packet
static void drain_packet(AVPacket *pkt, int drain_data, int drain_samples)
Definition: pcm_rechunk_bsf.c:89