aboutsummaryrefslogtreecommitdiffstats
path: root/libavcodec/pcm_rechunk_bsf.c
blob: 32a90cd2f737e5ed7f9aa23664d53dbf46a7c96f (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
/*
 * Copyright (c) 2020 Marton Balint
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include "avcodec.h"
#include "bsf.h"
#include "bsf_internal.h"
#include "libavutil/avassert.h"
#include "libavutil/opt.h"

typedef struct PCMContext {
    const AVClass *class;

    int nb_out_samples;
    int pad;
    AVRational frame_rate;

    AVPacket *in_pkt;
    AVPacket *out_pkt;
    int sample_size;
    int64_t n;
} PCMContext;

static int init(AVBSFContext *ctx)
{
    PCMContext *s = ctx->priv_data;
    AVRational sr = av_make_q(ctx->par_in->sample_rate, 1);
    int64_t min_samples;

    if (ctx->par_in->channels <= 0 || ctx->par_in->sample_rate <= 0)
        return AVERROR(EINVAL);

    ctx->time_base_out = av_inv_q(sr);
    s->sample_size = ctx->par_in->channels * av_get_bits_per_sample(ctx->par_in->codec_id) / 8;

    if (s->frame_rate.num) {
        min_samples = av_rescale_q_rnd(1, sr, s->frame_rate, AV_ROUND_DOWN);
    } else {
        min_samples = s->nb_out_samples;
    }
    if (min_samples <= 0 || min_samples > INT_MAX / s->sample_size - 1)
        return AVERROR(EINVAL);

    s->in_pkt  = av_packet_alloc();
    s->out_pkt = av_packet_alloc();
    if (!s->in_pkt || !s->out_pkt)
        return AVERROR(ENOMEM);

    return 0;
}

static void uninit(AVBSFContext *ctx)
{
    PCMContext *s = ctx->priv_data;
    av_packet_free(&s->in_pkt);
    av_packet_free(&s->out_pkt);
}

static void flush(AVBSFContext *ctx)
{
    PCMContext *s = ctx->priv_data;
    av_packet_unref(s->in_pkt);
    av_packet_unref(s->out_pkt);
    s->n = 0;
}

static int send_packet(PCMContext *s, int nb_samples, AVPacket *pkt)
{
    pkt->duration = nb_samples;
    s->n++;
    return 0;
}

static void drain_packet(AVPacket *pkt, int drain_data, int drain_samples)
{
    pkt->size -= drain_data;
    pkt->data += drain_data;
    if (pkt->dts != AV_NOPTS_VALUE)
        pkt->dts += drain_samples;
    if (pkt->pts != AV_NOPTS_VALUE)
        pkt->pts += drain_samples;
}

static int get_next_nb_samples(AVBSFContext *ctx)
{
    PCMContext *s = ctx->priv_data;
    if (s->frame_rate.num) {
        AVRational sr = av_make_q(ctx->par_in->sample_rate, 1);
        return av_rescale_q(s->n + 1, sr, s->frame_rate) - av_rescale_q(s->n, sr, s->frame_rate);
    } else {
        return s->nb_out_samples;
    }
}

static int rechunk_filter(AVBSFContext *ctx, AVPacket *pkt)
{
    PCMContext *s = ctx->priv_data;
    int nb_samples = get_next_nb_samples(ctx);
    int data_size = nb_samples * s->sample_size;
    int ret;

    do {
        if (s->in_pkt->size) {
            if (s->out_pkt->size || s->in_pkt->size < data_size) {
                int drain = FFMIN(s->in_pkt->size, data_size - s->out_pkt->size);
                if (!s->out_pkt->size) {
                    ret = av_new_packet(s->out_pkt, data_size);
                    if (ret < 0)
                        return ret;
                    ret = av_packet_copy_props(s->out_pkt, s->in_pkt);
                    if (ret < 0) {
                        av_packet_unref(s->out_pkt);
                        return ret;
                    }
                    s->out_pkt->size = 0;
                }
                memcpy(s->out_pkt->data + s->out_pkt->size, s->in_pkt->data, drain);
                s->out_pkt->size += drain;
                drain_packet(s->in_pkt, drain, drain / s->sample_size);
                if (!s->in_pkt->size)
                    av_packet_unref(s->in_pkt);
                if (s->out_pkt->size == data_size) {
                    av_packet_move_ref(pkt, s->out_pkt);
                    return send_packet(s, nb_samples, pkt);
                }
            } else if (s->in_pkt->size > data_size) {
                ret = av_packet_ref(pkt, s->in_pkt);
                if (ret < 0)
                    return ret;
                pkt->size = data_size;
                drain_packet(s->in_pkt, data_size, nb_samples);
                return send_packet(s, nb_samples, pkt);
            } else {
                av_assert0(s->in_pkt->size == data_size);
                av_packet_move_ref(pkt, s->in_pkt);
                return send_packet(s, nb_samples, pkt);
            }
        }

        ret = ff_bsf_get_packet_ref(ctx, s->in_pkt);
        if (ret == AVERROR_EOF && s->out_pkt->size) {
            if (s->pad) {
                memset(s->out_pkt->data + s->out_pkt->size, 0, data_size - s->out_pkt->size);
                s->out_pkt->size = data_size;
            } else {
                nb_samples = s->out_pkt->size / s->sample_size;
            }
            av_packet_move_ref(pkt, s->out_pkt);
            return send_packet(s, nb_samples, pkt);
        }
        if (ret >= 0)
            av_packet_rescale_ts(s->in_pkt, ctx->time_base_in, ctx->time_base_out);
    } while (ret >= 0);

    return ret;
}

#define OFFSET(x) offsetof(PCMContext, x)
#define FLAGS (AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_BSF_PARAM)
static const AVOption options[] = {
    { "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 },
    { "n",              "set the number of per-packet output samples", OFFSET(nb_out_samples),   AV_OPT_TYPE_INT, {.i64=1024}, 1, INT_MAX, FLAGS },
    { "pad",            "pad last packet with zeros",                  OFFSET(pad),             AV_OPT_TYPE_BOOL, {.i64=1} ,   0,       1, FLAGS },
    { "p",              "pad last packet with zeros",                  OFFSET(pad),             AV_OPT_TYPE_BOOL, {.i64=1} ,   0,       1, FLAGS },
    { "frame_rate",     "set number of packets per second",            OFFSET(frame_rate),  AV_OPT_TYPE_RATIONAL, {.dbl=0},    0, INT_MAX, FLAGS },
    { "r",              "set number of packets per second",            OFFSET(frame_rate),  AV_OPT_TYPE_RATIONAL, {.dbl=0},    0, INT_MAX, FLAGS },
    { NULL },
};

static const AVClass pcm_rechunk_class = {
    .class_name = "pcm_rechunk_bsf",
    .item_name  = av_default_item_name,
    .option     = options,
    .version    = LIBAVUTIL_VERSION_INT,
};

static const enum AVCodecID codec_ids[] = {
    AV_CODEC_ID_PCM_S16LE,
    AV_CODEC_ID_PCM_S16BE,
    AV_CODEC_ID_PCM_S8,
    AV_CODEC_ID_PCM_S32LE,
    AV_CODEC_ID_PCM_S32BE,
    AV_CODEC_ID_PCM_S24LE,
    AV_CODEC_ID_PCM_S24BE,
    AV_CODEC_ID_PCM_F32BE,
    AV_CODEC_ID_PCM_F32LE,
    AV_CODEC_ID_PCM_F64BE,
    AV_CODEC_ID_PCM_F64LE,
    AV_CODEC_ID_PCM_S64LE,
    AV_CODEC_ID_PCM_S64BE,
    AV_CODEC_ID_PCM_F16LE,
    AV_CODEC_ID_PCM_F24LE,
    AV_CODEC_ID_NONE,
};

const AVBitStreamFilter ff_pcm_rechunk_bsf = {
    .name           = "pcm_rechunk",
    .priv_data_size = sizeof(PCMContext),
    .priv_class     = &pcm_rechunk_class,
    .filter         = rechunk_filter,
    .init           = init,
    .flush          = flush,
    .close          = uninit,
    .codec_ids      = codec_ids,
};