FFmpeg
pcm_rechunk.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 
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->ch_layout.nb_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->ch_layout.nb_channels *
50  av_get_bits_per_sample(ctx->par_in->codec_id) / 8;
51 
52  if (s->frame_rate.num) {
53  min_samples = av_rescale_q_rnd(1, sr, s->frame_rate, AV_ROUND_DOWN);
54  } else {
55  min_samples = s->nb_out_samples;
56  }
57  if (min_samples <= 0 || min_samples > INT_MAX / s->sample_size - 1)
58  return AVERROR(EINVAL);
59 
60  s->in_pkt = av_packet_alloc();
61  s->out_pkt = av_packet_alloc();
62  if (!s->in_pkt || !s->out_pkt)
63  return AVERROR(ENOMEM);
64 
65  return 0;
66 }
67 
68 static void uninit(AVBSFContext *ctx)
69 {
71  av_packet_free(&s->in_pkt);
72  av_packet_free(&s->out_pkt);
73 }
74 
75 static void flush(AVBSFContext *ctx)
76 {
78  av_packet_unref(s->in_pkt);
79  av_packet_unref(s->out_pkt);
80  s->n = 0;
81 }
82 
83 static int send_packet(PCMContext *s, int nb_samples, AVPacket *pkt)
84 {
85  pkt->duration = nb_samples;
86  s->n++;
87  return 0;
88 }
89 
90 static void drain_packet(AVPacket *pkt, int drain_data, int drain_samples)
91 {
92  pkt->size -= drain_data;
93  pkt->data += drain_data;
94  if (pkt->dts != AV_NOPTS_VALUE)
95  pkt->dts += drain_samples;
96  if (pkt->pts != AV_NOPTS_VALUE)
97  pkt->pts += drain_samples;
98 }
99 
101 {
103  if (s->frame_rate.num) {
104  AVRational sr = av_make_q(ctx->par_in->sample_rate, 1);
105  return av_rescale_q(s->n + 1, sr, s->frame_rate) - av_rescale_q(s->n, sr, s->frame_rate);
106  } else {
107  return s->nb_out_samples;
108  }
109 }
110 
111 static void set_silence(AVCodecParameters *par, uint8_t *buf, size_t size)
112 {
113  int c = 0;
114  switch (par->codec_id) {
115  case AV_CODEC_ID_PCM_ALAW: c = 0xd5; break;
117  case AV_CODEC_ID_PCM_VIDC: c = 0xff; break;
118  case AV_CODEC_ID_PCM_U8: c = 0x80; break;
119  }
120  memset(buf, c, size);
121 }
122 
124 {
126  int nb_samples = get_next_nb_samples(ctx);
127  int data_size = nb_samples * s->sample_size;
128  int ret;
129 
130  do {
131  if (s->in_pkt->size) {
132  if (s->out_pkt->size || s->in_pkt->size < data_size) {
133  int drain = FFMIN(s->in_pkt->size, data_size - s->out_pkt->size);
134  if (!s->out_pkt->size) {
135  ret = av_new_packet(s->out_pkt, data_size);
136  if (ret < 0)
137  return ret;
138  ret = av_packet_copy_props(s->out_pkt, s->in_pkt);
139  if (ret < 0) {
140  av_packet_unref(s->out_pkt);
141  return ret;
142  }
143  s->out_pkt->size = 0;
144  }
145  memcpy(s->out_pkt->data + s->out_pkt->size, s->in_pkt->data, drain);
146  s->out_pkt->size += drain;
147  drain_packet(s->in_pkt, drain, drain / s->sample_size);
148  if (!s->in_pkt->size)
149  av_packet_unref(s->in_pkt);
150  if (s->out_pkt->size == data_size) {
151  av_packet_move_ref(pkt, s->out_pkt);
152  return send_packet(s, nb_samples, pkt);
153  }
154  av_assert0(!s->in_pkt->size);
155  } else if (s->in_pkt->size > data_size) {
156  ret = av_packet_ref(pkt, s->in_pkt);
157  if (ret < 0)
158  return ret;
159  pkt->size = data_size;
160  drain_packet(s->in_pkt, data_size, nb_samples);
161  return send_packet(s, nb_samples, pkt);
162  } else {
163  av_assert0(s->in_pkt->size == data_size);
164  av_packet_move_ref(pkt, s->in_pkt);
165  return send_packet(s, nb_samples, pkt);
166  }
167  } else
168  av_packet_unref(s->in_pkt);
169 
170  ret = ff_bsf_get_packet_ref(ctx, s->in_pkt);
171  if (ret == AVERROR_EOF && s->out_pkt->size) {
172  if (s->pad) {
173  set_silence(ctx->par_in, s->out_pkt->data + s->out_pkt->size, data_size - s->out_pkt->size);
174  s->out_pkt->size = data_size;
175  } else {
176  nb_samples = s->out_pkt->size / s->sample_size;
177  }
178  av_packet_move_ref(pkt, s->out_pkt);
179  return send_packet(s, nb_samples, pkt);
180  }
181  if (ret >= 0)
182  av_packet_rescale_ts(s->in_pkt, ctx->time_base_in, ctx->time_base_out);
183  } while (ret >= 0);
184 
185  return ret;
186 }
187 
188 #define OFFSET(x) offsetof(PCMContext, x)
189 #define FLAGS (AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_BSF_PARAM)
190 static const AVOption options[] = {
191  { "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 },
192  { "n", "set the number of per-packet output samples", OFFSET(nb_out_samples), AV_OPT_TYPE_INT, {.i64=1024}, 1, INT_MAX, FLAGS },
193  { "pad", "pad last packet with zeros", OFFSET(pad), AV_OPT_TYPE_BOOL, {.i64=1} , 0, 1, FLAGS },
194  { "p", "pad last packet with zeros", OFFSET(pad), AV_OPT_TYPE_BOOL, {.i64=1} , 0, 1, FLAGS },
195  { "frame_rate", "set number of packets per second", OFFSET(frame_rate), AV_OPT_TYPE_RATIONAL, {.dbl=0}, 0, INT_MAX, FLAGS },
196  { "r", "set number of packets per second", OFFSET(frame_rate), AV_OPT_TYPE_RATIONAL, {.dbl=0}, 0, INT_MAX, FLAGS },
197  { NULL },
198 };
199 
200 static const AVClass pcm_rechunk_class = {
201  .class_name = "pcm_rechunk_bsf",
202  .item_name = av_default_item_name,
203  .option = options,
204  .version = LIBAVUTIL_VERSION_INT,
205 };
206 
207 static const enum AVCodecID codec_ids[] = {
230 };
231 
233  .p.name = "pcm_rechunk",
234  .p.codec_ids = codec_ids,
235  .p.priv_class = &pcm_rechunk_class,
236  .priv_data_size = sizeof(PCMContext),
238  .init = init,
239  .flush = flush,
240  .close = uninit,
241 };
AV_CODEC_ID_PCM_S16LE
@ AV_CODEC_ID_PCM_S16LE
Definition: codec_id.h:334
av_packet_unref
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: packet.c:429
PCMContext::nb_out_samples
int nb_out_samples
Definition: pcm_rechunk.c:29
AV_CODEC_ID_PCM_F32BE
@ AV_CODEC_ID_PCM_F32BE
Definition: codec_id.h:354
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
AVCodecParameters
This struct describes the properties of an encoded stream.
Definition: codec_par.h:47
ff_pcm_rechunk_bsf
const FFBitStreamFilter ff_pcm_rechunk_bsf
Definition: pcm_rechunk.c:232
AVERROR_EOF
#define AVERROR_EOF
End of file.
Definition: error.h:57
AVBitStreamFilter::name
const char * name
Definition: bsf.h:112
int64_t
long long int64_t
Definition: coverity.c:34
FLAGS
#define FLAGS
Definition: pcm_rechunk.c:189
AVPacket::data
uint8_t * data
Definition: packet.h:539
AVOption
AVOption.
Definition: opt.h:429
set_silence
static void set_silence(AVCodecParameters *par, uint8_t *buf, size_t size)
Definition: pcm_rechunk.c:111
AV_CODEC_ID_PCM_SGA
@ AV_CODEC_ID_PCM_SGA
Definition: codec_id.h:370
filter
void(* filter)(uint8_t *src, int stride, int qscale)
Definition: h263dsp.c:29
drain_packet
static void drain_packet(AVPacket *pkt, int drain_data, int drain_samples)
Definition: pcm_rechunk.c:90
AVPacket::duration
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: packet.h:557
PCMContext::sample_size
int sample_size
Definition: pcm_rechunk.c:35
AV_OPT_TYPE_RATIONAL
@ AV_OPT_TYPE_RATIONAL
Underlying C type is AVRational.
Definition: opt.h:280
av_packet_free
void av_packet_free(AVPacket **pkt)
Free the packet, if the packet is reference counted, it will be unreferenced first.
Definition: packet.c:74
AVBSFContext
The bitstream filter state.
Definition: bsf.h:68
AV_CODEC_ID_PCM_S64LE
@ AV_CODEC_ID_PCM_S64LE
Definition: codec_id.h:365
bsf.h
AV_CODEC_ID_PCM_S16BE
@ AV_CODEC_ID_PCM_S16BE
Definition: codec_id.h:335
init
static int init(AVBSFContext *ctx)
Definition: pcm_rechunk.c:39
options
static const AVOption options[]
Definition: pcm_rechunk.c:190
av_get_bits_per_sample
int av_get_bits_per_sample(enum AVCodecID codec_id)
Return codec bits per sample.
Definition: utils.c:550
AV_CODEC_ID_PCM_S8
@ AV_CODEC_ID_PCM_S8
Definition: codec_id.h:338
avassert.h
pkt
AVPacket * pkt
Definition: movenc.c:60
s
#define s(width, name)
Definition: cbs_vp9.c:198
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: packet.c:98
av_assert0
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:40
pcm_rechunk_class
static const AVClass pcm_rechunk_class
Definition: pcm_rechunk.c:200
ctx
AVFormatContext * ctx
Definition: movenc.c:49
AV_CODEC_ID_PCM_F24LE
@ AV_CODEC_ID_PCM_F24LE
Definition: codec_id.h:368
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:142
AV_CODEC_ID_PCM_MULAW
@ AV_CODEC_ID_PCM_MULAW
Definition: codec_id.h:340
rechunk_filter
static int rechunk_filter(AVBSFContext *ctx, AVPacket *pkt)
Definition: pcm_rechunk.c:123
AV_CODEC_ID_PCM_ALAW
@ AV_CODEC_ID_PCM_ALAW
Definition: codec_id.h:341
LIBAVUTIL_VERSION_INT
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:75
NULL
#define NULL
Definition: coverity.c:32
FFBitStreamFilter
Definition: bsf_internal.h:27
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:237
AV_CODEC_ID_PCM_S64BE
@ AV_CODEC_ID_PCM_S64BE
Definition: codec_id.h:366
options
Definition: swscale.c:42
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: packet.c:437
av_packet_move_ref
void av_packet_move_ref(AVPacket *dst, AVPacket *src)
Move every field in src to dst and reset src.
Definition: packet.c:486
c
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
AVCodecID
AVCodecID
Identify the syntax and semantics of the bitstream.
Definition: codec_id.h:49
AV_CODEC_ID_PCM_VIDC
@ AV_CODEC_ID_PCM_VIDC
Definition: codec_id.h:369
AV_ROUND_DOWN
@ AV_ROUND_DOWN
Round toward -infinity.
Definition: mathematics.h:133
FFBitStreamFilter::p
AVBitStreamFilter p
The public AVBitStreamFilter.
Definition: bsf_internal.h:31
AV_CODEC_ID_PCM_S24LE
@ AV_CODEC_ID_PCM_S24LE
Definition: codec_id.h:346
PCMContext::in_pkt
AVPacket * in_pkt
Definition: pcm_rechunk.c:33
AVPacket::size
int size
Definition: packet.h:540
PCMContext::n
int64_t n
Definition: pcm_rechunk.c:36
size
int size
Definition: twinvq_data.h:10344
PCMContext
Definition: pcm_rechunk.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:538
send_packet
static int send_packet(PCMContext *s, int nb_samples, AVPacket *pkt)
Definition: pcm_rechunk.c:83
av_packet_alloc
AVPacket * av_packet_alloc(void)
Allocate an AVPacket and set its fields to default values.
Definition: packet.c:63
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: packet.c:533
codec_ids
static enum AVCodecID codec_ids[]
Definition: pcm_rechunk.c:207
uninit
static void uninit(AVBSFContext *ctx)
Definition: pcm_rechunk.c:68
av_packet_copy_props
int av_packet_copy_props(AVPacket *dst, const AVPacket *src)
Copy only "properties" fields from src to dst.
Definition: packet.c:392
AV_CODEC_ID_NONE
@ AV_CODEC_ID_NONE
Definition: codec_id.h:50
AVPacket::pts
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: packet.h:532
OFFSET
#define OFFSET(x)
Definition: pcm_rechunk.c:188
AV_CODEC_ID_PCM_F64BE
@ AV_CODEC_ID_PCM_F64BE
Definition: codec_id.h:356
FFMIN
#define FFMIN(a, b)
Definition: macros.h:49
AV_CODEC_ID_PCM_S32BE
@ AV_CODEC_ID_PCM_S32BE
Definition: codec_id.h:343
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:367
PCMContext::pad
int pad
Definition: pcm_rechunk.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:80
AV_OPT_TYPE_INT
@ AV_OPT_TYPE_INT
Underlying C type is int.
Definition: opt.h:259
AV_CODEC_ID_PCM_S32LE
@ AV_CODEC_ID_PCM_S32LE
Definition: codec_id.h:342
AV_CODEC_ID_PCM_U8
@ AV_CODEC_ID_PCM_U8
Definition: codec_id.h:339
get_next_nb_samples
static int get_next_nb_samples(AVBSFContext *ctx)
Definition: pcm_rechunk.c:100
flush
static void flush(AVBSFContext *ctx)
Definition: pcm_rechunk.c:75
AV_CODEC_ID_PCM_S24DAUD
@ AV_CODEC_ID_PCM_S24DAUD
Definition: codec_id.h:350
AV_CODEC_ID_PCM_F64LE
@ AV_CODEC_ID_PCM_F64LE
Definition: codec_id.h:357
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:55
AVPacket
This structure stores compressed data.
Definition: packet.h:516
AV_OPT_TYPE_BOOL
@ AV_OPT_TYPE_BOOL
Underlying C type is int.
Definition: opt.h:327
AV_CODEC_ID_PCM_F32LE
@ AV_CODEC_ID_PCM_F32LE
Definition: codec_id.h:355
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:256
AVFormatContext::priv_data
void * priv_data
Format private data.
Definition: avformat.h:1328
AV_CODEC_ID_PCM_S24BE
@ AV_CODEC_ID_PCM_S24BE
Definition: codec_id.h:347
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:134
PCMContext::out_pkt
AVPacket * out_pkt
Definition: pcm_rechunk.c:34
PCMContext::frame_rate
AVRational frame_rate
Definition: pcm_rechunk.c:31