summaryrefslogtreecommitdiffstats
path: root/common/av_common.c
blob: 1a162b7d95be4b0328d127d6fafe155cc4253ca0 (plain)
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
/*
 * This file is part of mpv.
 *
 * mpv is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * mpv 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with mpv.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <assert.h>

#include <libavutil/common.h>
#include <libavutil/log.h>
#include <libavcodec/avcodec.h>

#include "common/common.h"
#include "common/msg.h"
#include "demux/packet.h"
#include "av_common.h"
#include "codecs.h"

#include "osdep/numcores.h"

int mp_lavc_set_extradata(AVCodecContext *avctx, void *ptr, int size)
{
    if (size) {
        av_free(avctx->extradata);
        avctx->extradata_size = 0;
        avctx->extradata = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE);
        if (!avctx->extradata)
            return -1;
        avctx->extradata_size = size;
        memcpy(avctx->extradata, ptr, size);
    }
    return 0;
}

// Copy the codec-related fields from st into avctx. This does not set the
// codec itself, only codec related header data provided by libavformat.
// The goal is to initialize a new decoder with the header data provided by
// libavformat, and unlike avcodec_copy_context(), allow the user to create
// a clean AVCodecContext for a manually selected AVCodec.
// This is strictly for decoding only.
void mp_copy_lav_codec_headers(AVCodecContext *avctx, AVCodecContext *st)
{
    mp_lavc_set_extradata(avctx, st->extradata, st->extradata_size);
    avctx->codec_tag                = st->codec_tag;
    avctx->stream_codec_tag         = st->stream_codec_tag;
    avctx->bit_rate                 = st->bit_rate;
    avctx->width                    = st->width;
    avctx->height                   = st->height;
    avctx->pix_fmt                  = st->pix_fmt;
    avctx->sample_aspect_ratio      = st->sample_aspect_ratio;
    avctx->chroma_sample_location   = st->chroma_sample_location;
    avctx->sample_rate              = st->sample_rate;
    avctx->channels                 = st->channels;
    avctx->block_align              = st->block_align;
    avctx->channel_layout           = st->channel_layout;
    avctx->audio_service_type       = st->audio_service_type;
    avctx->bits_per_coded_sample    = st->bits_per_coded_sample;
}

// We merely pass-through our PTS/DTS as an int64_t; libavcodec won't use it.
union pts { int64_t i; double d; };

// Convert the mpv style timestamp (seconds as double) to a libavcodec style
// timestamp (integer units in a given timebase).
//
// If the given timebase is NULL or invalid, pass through the mpv timestamp by
// reinterpret casting them to int64_t. In this case, the timestamps will be
// non-sense for libavcodec, but we expect that it doesn't interpret them,
// and treats them as opaque.
int64_t mp_pts_to_av(double mp_pts, AVRational *tb)
{
    assert(sizeof(int64_t) >= sizeof(double));
    if (tb && tb->num > 0 && tb->den > 0)
        return mp_pts == MP_NOPTS_VALUE ? AV_NOPTS_VALUE : mp_pts / av_q2d(*tb);
    // The + 0.0 is to squash possible negative zero mp_pts, which would
    // happen to end up as AV_NOPTS_VALUE.
    return (union pts){.d = mp_pts + 0.0}.i;
}

// Inverse of mp_pts_to_av(). (The timebases must be exactly the same.)
double mp_pts_from_av(int64_t av_pts, AVRational *tb)
{
    assert(sizeof(int64_t) >= sizeof(double));
    if (tb && tb->num > 0 && tb->den > 0)
        return av_pts == AV_NOPTS_VALUE ? MP_NOPTS_VALUE : av_pts * av_q2d(*tb);
    // Should libavcodec set the PTS to AV_NOPTS_VALUE, it would end up as
    // non-sense (usually negative zero) when unwrapped to double.
    return av_pts == AV_NOPTS_VALUE ? MP_NOPTS_VALUE : (union pts){.i = av_pts}.d;
}

// Set dst from mpkt. Note that dst is not refcountable.
// mpkt can be NULL to generate empty packets (used to flush delayed data).
// Sets pts/dts using mp_pts_to_av(ts, tb). (Be aware of the implications.)
// Set duration field only if tb is set.
void mp_set_av_packet(AVPacket *dst, struct demux_packet *mpkt, AVRational *tb)
{
    av_init_packet(dst);
    dst->data = mpkt ? mpkt->buffer : NULL;
    dst->size = mpkt ? mpkt->len : 0;
    /* Some codecs (ZeroCodec, some cases of PNG) may want keyframe info
     * from demuxer. */
    if (mpkt && mpkt->keyframe)
        dst->flags |= AV_PKT_FLAG_KEY;
    if (mpkt && mpkt->avpacket) {
        dst->side_data = mpkt->avpacket->side_data;
        dst->side_data_elems = mpkt->avpacket->side_data_elems;
    }
    if (mpkt && tb && tb->num > 0 && tb->den > 0)
        dst->duration = mpkt->duration / av_q2d(*tb);
    dst->pts = mp_pts_to_av(mpkt ? mpkt->pts : MP_NOPTS_VALUE, tb);
    dst->dts = mp_pts_to_av(mpkt ? mpkt->dts : MP_NOPTS_VALUE, tb);
}

void mp_set_avcodec_threads(AVCodecContext *avctx, int threads)
{
    if (threads == 0) {
        threads = default_thread_count();
        if (threads < 1) {
            av_log(avctx, AV_LOG_WARNING, "Could not determine "
                   "thread count to use, defaulting to 1.\n");
            threads = 1;
        }
        // Apparently some libavcodec versions have or had trouble with more
        // than 16 threads, and/or print a warning when using > 16.
        threads = MPMIN(threads, 16);
    }
    avctx->thread_count = threads;
}

void mp_add_lavc_decoders(struct mp_decoder_list *list, enum AVMediaType type)
{
    AVCodec *cur = NULL;
    for (;;) {
        cur = av_codec_next(cur);
        if (!cur)
            break;
        if (av_codec_is_decoder(cur) && cur->type == type) {
            mp_add_decoder(list, "lavc", mp_codec_from_av_codec_id(cur->id),
                           cur->name, cur->long_name);
        }
    }
}

int mp_codec_to_av_codec_id(const char *codec)
{
    int id = AV_CODEC_ID_NONE;
    if (codec) {
        const AVCodecDescriptor *desc = avcodec_descriptor_get_by_name(codec);
        if (desc)
            id = desc->id;
        if (id == AV_CODEC_ID_NONE) {
            AVCodec *avcodec = avcodec_find_decoder_by_name(codec);
            if (avcodec)
                id = avcodec->id;
        }
    }
    return id;
}

const char *mp_codec_from_av_codec_id(int codec_id)
{
    const char *name = NULL;
    const AVCodecDescriptor *desc = avcodec_descriptor_get(codec_id);
    if (desc)
        name = desc->name;
    if (!name) {
        AVCodec *avcodec = avcodec_find_decoder(codec_id);
        if (avcodec)
            name = avcodec->name;
    }
    return name;
}