FFmpeg coverage

GCC Code Coverage Report

Directory:	../../../ffmpeg/		Exec	Total	Coverage
File:	src/libavfilter/af_pan.c	Lines:	178	229	77.7 %
Date:	2021-04-15 16:04:23	Branches:	105	140	75.0 %


/*
 * Copyright (c) 2002 Anders Johansson <ajh@atri.curtin.edu.au>
 * Copyright (c) 2011 Clément Bœsch <u pkh me>
 * Copyright (c) 2011 Nicolas George <nicolas.george@normalesup.org>
 *
 * 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
 */

/**
 * @file
 * Audio panning filter (channels mixing)
 * Original code written by Anders Johansson for MPlayer,
 * reimplemented for FFmpeg.
 */

#include <stdio.h>
#include "libavutil/avstring.h"
#include "libavutil/channel_layout.h"
#include "libavutil/opt.h"
#include "libswresample/swresample.h"
#include "audio.h"
#include "avfilter.h"
#include "formats.h"
#include "internal.h"

#define MAX_CHANNELS 64

typedef struct PanContext {
    const AVClass *class;
    char *args;
    int64_t out_channel_layout;
    double gain[MAX_CHANNELS][MAX_CHANNELS];
    int64_t need_renorm;
    int need_renumber;
    int nb_output_channels;

    int pure_gains;
    /* channel mapping specific */
    int channel_map[MAX_CHANNELS];
    struct SwrContext *swr;
} PanContext;

static void skip_spaces(char **arg)
{
    int len = 0;

    sscanf(*arg, " %n", &len);
    *arg += len;
}

static int parse_channel_name(char **arg, int *rchannel, int *rnamed)
{
    char buf[8];
    int len, i, channel_id = 0;
    int64_t layout, layout0;

    skip_spaces(arg);
    /* try to parse a channel name, e.g. "FL" */
    if (sscanf(*arg, "%7[A-Z]%n", buf, &len)) {
        layout0 = layout = av_get_channel_layout(buf);
        /* channel_id <- first set bit in layout */
        for (i = 32; i > 0; i >>= 1) {
            if (layout >= (int64_t)1 << i) {
                channel_id += i;
                layout >>= i;
            }
        }
        /* reject layouts that are not a single channel */
        if (channel_id >= MAX_CHANNELS || layout0 != (int64_t)1 << channel_id)
            return AVERROR(EINVAL);
        *rchannel = channel_id;
        *rnamed = 1;
        *arg += len;
        return 0;
    }
    /* try to parse a channel number, e.g. "c2" */
    if (sscanf(*arg, "c%d%n", &channel_id, &len) &&
        channel_id >= 0 && channel_id < MAX_CHANNELS) {
        *rchannel = channel_id;
        *rnamed = 0;
        *arg += len;
        return 0;
    }
    return AVERROR(EINVAL);
}

static av_cold int init(AVFilterContext *ctx)
{
    PanContext *const pan = ctx->priv;
    char *arg, *arg0, *tokenizer, *args = av_strdup(pan->args);
    int out_ch_id, in_ch_id, len, named, ret, sign = 1;
    int nb_in_channels[2] = { 0, 0 }; // number of unnamed and named input channels
    int used_out_ch[MAX_CHANNELS] = {0};
    double gain;

    if (!pan->args) {
        av_log(ctx, AV_LOG_ERROR,
               "pan filter needs a channel layout and a set "
               "of channel definitions as parameter\n");
        return AVERROR(EINVAL);
    }
    if (!args)
        return AVERROR(ENOMEM);
    arg = av_strtok(args, "|", &tokenizer);
    if (!arg) {
        av_log(ctx, AV_LOG_ERROR, "Channel layout not specified\n");
        ret = AVERROR(EINVAL);
        goto fail;
    }
    ret = ff_parse_channel_layout(&pan->out_channel_layout,
                                  &pan->nb_output_channels, arg, ctx);
    if (ret < 0)
        goto fail;

    /* parse channel specifications */
    while ((arg = arg0 = av_strtok(NULL, "|", &tokenizer))) {
        int used_in_ch[MAX_CHANNELS] = {0};
        /* channel name */
        if (parse_channel_name(&arg, &out_ch_id, &named)) {
            av_log(ctx, AV_LOG_ERROR,
                   "Expected out channel name, got \"%.8s\"\n", arg);
            ret = AVERROR(EINVAL);
            goto fail;
        }
        if (named) {
            if (!((pan->out_channel_layout >> out_ch_id) & 1)) {
                av_log(ctx, AV_LOG_ERROR,
                       "Channel \"%.8s\" does not exist in the chosen layout\n", arg0);
                ret = AVERROR(EINVAL);
                goto fail;
            }
            /* get the channel number in the output channel layout:
             * out_channel_layout & ((1 << out_ch_id) - 1) are all the
             * channels that come before out_ch_id,
             * so their count is the index of out_ch_id */
            out_ch_id = av_get_channel_layout_nb_channels(pan->out_channel_layout & (((int64_t)1 << out_ch_id) - 1));
        }
        if (out_ch_id < 0 || out_ch_id >= pan->nb_output_channels) {
            av_log(ctx, AV_LOG_ERROR,
                   "Invalid out channel name \"%.8s\"\n", arg0);
            ret = AVERROR(EINVAL);
            goto fail;
        }
        if (used_out_ch[out_ch_id]) {
            av_log(ctx, AV_LOG_ERROR,
                   "Can not reference out channel %d twice\n", out_ch_id);
            ret = AVERROR(EINVAL);
            goto fail;
        }
        used_out_ch[out_ch_id] = 1;
        skip_spaces(&arg);
        if (*arg == '=') {
            arg++;
        } else if (*arg == '<') {
            pan->need_renorm |= (int64_t)1 << out_ch_id;
            arg++;
        } else {
            av_log(ctx, AV_LOG_ERROR,
                   "Syntax error after channel name in \"%.8s\"\n", arg0);
            ret = AVERROR(EINVAL);
            goto fail;
        }
        /* gains */
        sign = 1;
        while (1) {
            gain = 1;
            if (sscanf(arg, "%lf%n *%n", &gain, &len, &len))
                arg += len;
            if (parse_channel_name(&arg, &in_ch_id, &named)){
                av_log(ctx, AV_LOG_ERROR,
                       "Expected in channel name, got \"%.8s\"\n", arg);
                 ret = AVERROR(EINVAL);
                 goto fail;
            }
            nb_in_channels[named]++;
            if (nb_in_channels[!named]) {
                av_log(ctx, AV_LOG_ERROR,
                       "Can not mix named and numbered channels\n");
                ret = AVERROR(EINVAL);
                goto fail;
            }
            if (used_in_ch[in_ch_id]) {
                av_log(ctx, AV_LOG_ERROR,
                       "Can not reference in channel %d twice\n", in_ch_id);
                ret = AVERROR(EINVAL);
                goto fail;
            }
            used_in_ch[in_ch_id] = 1;
            pan->gain[out_ch_id][in_ch_id] = sign * gain;
            skip_spaces(&arg);
            if (!*arg)
                break;
            if (*arg == '-') {
                sign = -1;
            } else if (*arg != '+') {
                av_log(ctx, AV_LOG_ERROR, "Syntax error near \"%.8s\"\n", arg);
                ret = AVERROR(EINVAL);
                goto fail;
            } else {
                sign = 1;
            }
            arg++;
        }
    }
    pan->need_renumber = !!nb_in_channels[1];

    ret = 0;
fail:
    av_free(args);
    return ret;
}

static int are_gains_pure(const PanContext *pan)
{
    int i, j;

    for (i = 0; i < MAX_CHANNELS; i++) {
        int nb_gain = 0;

        for (j = 0; j < MAX_CHANNELS; j++) {
            double gain = pan->gain[i][j];

            /* channel mapping is effective only if 0% or 100% of a channel is
             * selected... */
            if (gain != 0. && gain != 1.)
                return 0;
            /* ...and if the output channel is only composed of one input */
            if (gain && nb_gain++)
                return 0;
        }
    }
    return 1;
}

static int query_formats(AVFilterContext *ctx)
{
    PanContext *pan = ctx->priv;
    AVFilterLink *inlink  = ctx->inputs[0];
    AVFilterLink *outlink = ctx->outputs[0];
    AVFilterFormats *formats = NULL;
    AVFilterChannelLayouts *layouts;
    int ret;

    pan->pure_gains = are_gains_pure(pan);
    /* libswr supports any sample and packing formats */
    if ((ret = ff_set_common_formats(ctx, ff_all_formats(AVMEDIA_TYPE_AUDIO))) < 0)
        return ret;

    formats = ff_all_samplerates();
    if ((ret = ff_set_common_samplerates(ctx, formats)) < 0)
        return ret;

    // inlink supports any channel layout
    layouts = ff_all_channel_counts();
    if ((ret = ff_channel_layouts_ref(layouts, &inlink->outcfg.channel_layouts)) < 0)
        return ret;

    // outlink supports only requested output channel layout
    layouts = NULL;
    if ((ret = ff_add_channel_layout(&layouts,
                          pan->out_channel_layout ? pan->out_channel_layout :
                          FF_COUNT2LAYOUT(pan->nb_output_channels))) < 0)
        return ret;
    return ff_channel_layouts_ref(layouts, &outlink->incfg.channel_layouts);
}

static int config_props(AVFilterLink *link)
{
    AVFilterContext *ctx = link->dst;
    PanContext *pan = ctx->priv;
    char buf[1024], *cur;
    int i, j, k, r;
    double t;

    if (pan->need_renumber) {
        // input channels were given by their name: renumber them
        for (i = j = 0; i < MAX_CHANNELS; i++) {
            if ((link->channel_layout >> i) & 1) {
                for (k = 0; k < pan->nb_output_channels; k++)
                    pan->gain[k][j] = pan->gain[k][i];
                j++;
            }
        }
    }

    // sanity check; can't be done in query_formats since the inlink
    // channel layout is unknown at that time
    if (link->channels > MAX_CHANNELS ||
        pan->nb_output_channels > MAX_CHANNELS) {
        av_log(ctx, AV_LOG_ERROR,
               "af_pan supports a maximum of %d channels. "
               "Feel free to ask for a higher limit.\n", MAX_CHANNELS);
        return AVERROR_PATCHWELCOME;
    }

    // init libswresample context
    pan->swr = swr_alloc_set_opts(pan->swr,
                                  pan->out_channel_layout, link->format, link->sample_rate,
                                  link->channel_layout,    link->format, link->sample_rate,
                                  0, ctx);
    if (!pan->swr)
        return AVERROR(ENOMEM);
    if (!link->channel_layout) {
        if (av_opt_set_int(pan->swr, "ich", link->channels, 0) < 0)
            return AVERROR(EINVAL);
    }
    if (!pan->out_channel_layout) {
        if (av_opt_set_int(pan->swr, "och", pan->nb_output_channels, 0) < 0)
            return AVERROR(EINVAL);
    }

    // gains are pure, init the channel mapping
    if (pan->pure_gains) {

        // get channel map from the pure gains
        for (i = 0; i < pan->nb_output_channels; i++) {
            int ch_id = -1;
            for (j = 0; j < link->channels; j++) {
                if (pan->gain[i][j]) {
                    ch_id = j;
                    break;
                }
            }
            pan->channel_map[i] = ch_id;
        }

        av_opt_set_int(pan->swr, "icl", pan->out_channel_layout, 0);
        av_opt_set_int(pan->swr, "uch", pan->nb_output_channels, 0);
        swr_set_channel_mapping(pan->swr, pan->channel_map);
    } else {
        // renormalize
        for (i = 0; i < pan->nb_output_channels; i++) {
            if (!((pan->need_renorm >> i) & 1))
                continue;
            t = 0;
            for (j = 0; j < link->channels; j++)
                t += fabs(pan->gain[i][j]);
            if (t > -1E-5 && t < 1E-5) {
                // t is almost 0 but not exactly, this is probably a mistake
                if (t)
                    av_log(ctx, AV_LOG_WARNING,
                           "Degenerate coefficients while renormalizing\n");
                continue;
            }
            for (j = 0; j < link->channels; j++)
                pan->gain[i][j] /= t;
        }
        av_opt_set_int(pan->swr, "icl", link->channel_layout, 0);
        av_opt_set_int(pan->swr, "ocl", pan->out_channel_layout, 0);
        swr_set_matrix(pan->swr, pan->gain[0], pan->gain[1] - pan->gain[0]);
    }

    r = swr_init(pan->swr);
    if (r < 0)
        return r;

    // summary
    for (i = 0; i < pan->nb_output_channels; i++) {
        cur = buf;
        for (j = 0; j < link->channels; j++) {
            r = snprintf(cur, buf + sizeof(buf) - cur, "%s%.3g i%d",
                         j ? " + " : "", pan->gain[i][j], j);
            cur += FFMIN(buf + sizeof(buf) - cur, r);
        }
        av_log(ctx, AV_LOG_VERBOSE, "o%d = %s\n", i, buf);
    }
    // add channel mapping summary if possible
    if (pan->pure_gains) {
        av_log(ctx, AV_LOG_INFO, "Pure channel mapping detected:");
        for (i = 0; i < pan->nb_output_channels; i++)
            if (pan->channel_map[i] < 0)
                av_log(ctx, AV_LOG_INFO, " M");
            else
                av_log(ctx, AV_LOG_INFO, " %d", pan->channel_map[i]);
        av_log(ctx, AV_LOG_INFO, "\n");
        return 0;
    }
    return 0;
}

static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
{
    int ret;
    int n = insamples->nb_samples;
    AVFilterLink *const outlink = inlink->dst->outputs[0];
    AVFrame *outsamples = ff_get_audio_buffer(outlink, n);
    PanContext *pan = inlink->dst->priv;

    if (!outsamples) {
        av_frame_free(&insamples);
        return AVERROR(ENOMEM);
    }
    swr_convert(pan->swr, outsamples->extended_data, n,
                (void *)insamples->extended_data, n);
    av_frame_copy_props(outsamples, insamples);
    outsamples->channel_layout = outlink->channel_layout;
    outsamples->channels = outlink->channels;

    ret = ff_filter_frame(outlink, outsamples);
    av_frame_free(&insamples);
    return ret;
}

static av_cold void uninit(AVFilterContext *ctx)
{
    PanContext *pan = ctx->priv;
    swr_free(&pan->swr);
}

#define OFFSET(x) offsetof(PanContext, x)

static const AVOption pan_options[] = {
    { "args", NULL, OFFSET(args), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM },
    { NULL }
};

AVFILTER_DEFINE_CLASS(pan);

static const AVFilterPad pan_inputs[] = {
    {
        .name         = "default",
        .type         = AVMEDIA_TYPE_AUDIO,
        .config_props = config_props,
        .filter_frame = filter_frame,
    },
    { NULL }
};

static const AVFilterPad pan_outputs[] = {
    {
        .name = "default",
        .type = AVMEDIA_TYPE_AUDIO,
    },
    { NULL }
};

AVFilter ff_af_pan = {
    .name          = "pan",
    .description   = NULL_IF_CONFIG_SMALL("Remix channels with coefficients (panning)."),
    .priv_size     = sizeof(PanContext),
    .priv_class    = &pan_class,
    .init          = init,
    .uninit        = uninit,
    .query_formats = query_formats,
    .inputs        = pan_inputs,
    .outputs       = pan_outputs,
};


Generated by: GCOVR (Version 4.2)

Line	Branch	Exec	Source
1			/*
2			* Copyright (c) 2002 Anders Johansson <ajh@atri.curtin.edu.au>
3			* Copyright (c) 2011 Clément Bœsch <u pkh me>
4			* Copyright (c) 2011 Nicolas George <nicolas.george@normalesup.org>
5			*
6			* This file is part of FFmpeg.
7			*
8			* FFmpeg is free software; you can redistribute it and/or
9			* modify it under the terms of the GNU Lesser General Public
10			* License as published by the Free Software Foundation; either
11			* version 2.1 of the License, or (at your option) any later version.
12			*
13			* FFmpeg is distributed in the hope that it will be useful,
14			* but WITHOUT ANY WARRANTY; without even the implied warranty of
15			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16			* GNU Lesser General Public License for more details.
17			*
18			* You should have received a copy of the GNU Lesser General Public
19			* License along with FFmpeg; if not, write to the Free Software
20			* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21			*/
22
23			/**
24			* @file
25			* Audio panning filter (channels mixing)
26			* Original code written by Anders Johansson for MPlayer,
27			* reimplemented for FFmpeg.
28			*/
29
30			#include <stdio.h>
31			#include "libavutil/avstring.h"
32			#include "libavutil/channel_layout.h"
33			#include "libavutil/opt.h"
34			#include "libswresample/swresample.h"
35			#include "audio.h"
36			#include "avfilter.h"
37			#include "formats.h"
38			#include "internal.h"
39
40			#define MAX_CHANNELS 64
41
42			typedef struct PanContext {
43			const AVClass *class;
44			char *args;
45			int64_t out_channel_layout;
46			double gain[MAX_CHANNELS][MAX_CHANNELS];
47			int64_t need_renorm;
48			int need_renumber;
49			int nb_output_channels;
50
51			int pure_gains;
52			/* channel mapping specific */
53			int channel_map[MAX_CHANNELS];
54			struct SwrContext *swr;
55			} PanContext;
56
57		206	static void skip_spaces(char **arg)
58			{
59		206	int len = 0;
60
61		206	sscanf(*arg, " %n", &len);
62		206	*arg += len;
63		206	}
64
65		103	static int parse_channel_name(char *arg, int rchannel, int *rnamed)
66			{
67			char buf[8];
68		103	int len, i, channel_id = 0;
69			int64_t layout, layout0;
70
71		103	skip_spaces(arg);
72			/* try to parse a channel name, e.g. "FL" */
73	✓✓	103	if (sscanf(*arg, "%7[A-Z]%n", buf, &len)) {
74		18	layout0 = layout = av_get_channel_layout(buf);
75			/* channel_id <- first set bit in layout */
76	✓✓	126	for (i = 32; i > 0; i >>= 1) {
77	✓✓	108	if (layout >= (int64_t)1 << i) {
78		15	channel_id += i;
79		15	layout >>= i;
80			}
81			}
82			/* reject layouts that are not a single channel */
83	✓✗✗✓	18	if (channel_id >= MAX_CHANNELS \|\| layout0 != (int64_t)1 << channel_id)
84			return AVERROR(EINVAL);
85		18	*rchannel = channel_id;
86		18	*rnamed = 1;
87		18	*arg += len;
88		18	return 0;
89			}
90			/* try to parse a channel number, e.g. "c2" */
91	✓✗	85	if (sscanf(*arg, "c%d%n", &channel_id, &len) &&
92	✓✗✓✗	85	channel_id >= 0 && channel_id < MAX_CHANNELS) {
93		85	*rchannel = channel_id;
94		85	*rnamed = 0;
95		85	*arg += len;
96		85	return 0;
97			}
98			return AVERROR(EINVAL);
99			}
100
101		16	static av_cold int init(AVFilterContext *ctx)
102			{
103		16	PanContext *const pan = ctx->priv;
104		16	char arg, arg0, tokenizer, args = av_strdup(pan->args);
105		16	int out_ch_id, in_ch_id, len, named, ret, sign = 1;
106		16	int nb_in_channels[2] = { 0, 0 }; // number of unnamed and named input channels
107		16	int used_out_ch[MAX_CHANNELS] = {0};
108			double gain;
109
110	✗✓	16	if (!pan->args) {
111			av_log(ctx, AV_LOG_ERROR,
112			"pan filter needs a channel layout and a set "
113			"of channel definitions as parameter\n");
114			return AVERROR(EINVAL);
115			}
116	✗✓	16	if (!args)
117			return AVERROR(ENOMEM);
118		16	arg = av_strtok(args, "\|", &tokenizer);
119	✗✓	16	if (!arg) {
120			av_log(ctx, AV_LOG_ERROR, "Channel layout not specified\n");
121			ret = AVERROR(EINVAL);
122			goto fail;
123			}
124		16	ret = ff_parse_channel_layout(&pan->out_channel_layout,
125			&pan->nb_output_channels, arg, ctx);
126	✗✓	16	if (ret < 0)
127			goto fail;
128
129			/* parse channel specifications */
130	✓✓	55	while ((arg = arg0 = av_strtok(NULL, "\|", &tokenizer))) {
131		39	int used_in_ch[MAX_CHANNELS] = {0};
132			/* channel name */
133	✗✓	39	if (parse_channel_name(&arg, &out_ch_id, &named)) {
134			av_log(ctx, AV_LOG_ERROR,
135			"Expected out channel name, got \"%.8s\"\n", arg);
136			ret = AVERROR(EINVAL);
137			goto fail;
138			}
139	✓✓	39	if (named) {
140	✗✓	7	if (!((pan->out_channel_layout >> out_ch_id) & 1)) {
141			av_log(ctx, AV_LOG_ERROR,
142			"Channel \"%.8s\" does not exist in the chosen layout\n", arg0);
143			ret = AVERROR(EINVAL);
144			goto fail;
145			}
146			/* get the channel number in the output channel layout:
147			* out_channel_layout & ((1 << out_ch_id) - 1) are all the
148			* channels that come before out_ch_id,
149			* so their count is the index of out_ch_id */
150		7	out_ch_id = av_get_channel_layout_nb_channels(pan->out_channel_layout & (((int64_t)1 << out_ch_id) - 1));
151			}
152	✓✗✗✓	39	if (out_ch_id < 0 \|\| out_ch_id >= pan->nb_output_channels) {
153			av_log(ctx, AV_LOG_ERROR,
154			"Invalid out channel name \"%.8s\"\n", arg0);
155			ret = AVERROR(EINVAL);
156			goto fail;
157			}
158	✗✓	39	if (used_out_ch[out_ch_id]) {
159			av_log(ctx, AV_LOG_ERROR,
160			"Can not reference out channel %d twice\n", out_ch_id);
161			ret = AVERROR(EINVAL);
162			goto fail;
163			}
164		39	used_out_ch[out_ch_id] = 1;
165		39	skip_spaces(&arg);
166	✓✓	39	if (*arg == '=') {
167		35	arg++;
168	✓✗	4	} else if (*arg == '<') {
169		4	pan->need_renorm \|= (int64_t)1 << out_ch_id;
170		4	arg++;
171			} else {
172			av_log(ctx, AV_LOG_ERROR,
173			"Syntax error after channel name in \"%.8s\"\n", arg0);
174			ret = AVERROR(EINVAL);
175			goto fail;
176			}
177			/* gains */
178		39	sign = 1;
179			while (1) {
180		64	gain = 1;
181	✓✓	64	if (sscanf(arg, "%lf%n *%n", &gain, &len, &len))
182		18	arg += len;
183	✗✓	64	if (parse_channel_name(&arg, &in_ch_id, &named)){
184			av_log(ctx, AV_LOG_ERROR,
185			"Expected in channel name, got \"%.8s\"\n", arg);
186			ret = AVERROR(EINVAL);
187			goto fail;
188			}
189		64	nb_in_channels[named]++;
190	✗✓	64	if (nb_in_channels[!named]) {
191			av_log(ctx, AV_LOG_ERROR,
192			"Can not mix named and numbered channels\n");
193			ret = AVERROR(EINVAL);
194			goto fail;
195			}
196	✗✓	64	if (used_in_ch[in_ch_id]) {
197			av_log(ctx, AV_LOG_ERROR,
198			"Can not reference in channel %d twice\n", in_ch_id);
199			ret = AVERROR(EINVAL);
200			goto fail;
201			}
202		64	used_in_ch[in_ch_id] = 1;
203		64	pan->gain[out_ch_id][in_ch_id] = sign * gain;
204		64	skip_spaces(&arg);
205	✓✓	64	if (!*arg)
206		39	break;
207	✓✓	25	if (*arg == '-') {
208		9	sign = -1;
209	✗✓	16	} else if (*arg != '+') {
210			av_log(ctx, AV_LOG_ERROR, "Syntax error near \"%.8s\"\n", arg);
211			ret = AVERROR(EINVAL);
212			goto fail;
213			} else {
214		16	sign = 1;
215			}
216		25	arg++;
217			}
218			}
219		16	pan->need_renumber = !!nb_in_channels[1];
220
221		16	ret = 0;
222		16	fail:
223		16	av_free(args);
224		16	return ret;
225			}
226
227		16	static int are_gains_pure(const PanContext *pan)
228			{
229			int i, j;
230
231	✓✓	528	for (i = 0; i < MAX_CHANNELS; i++) {
232		520	int nb_gain = 0;
233
234	✓✓	33296	for (j = 0; j < MAX_CHANNELS; j++) {
235		32784	double gain = pan->gain[i][j];
236
237			/* channel mapping is effective only if 0% or 100% of a channel is
238			* selected... */
239	✓✓✓✓	32784	if (gain != 0. && gain != 1.)
240		7	return 0;
241			/* ...and if the output channel is only composed of one input */
242	✓✓✓✓	32777	if (gain && nb_gain++)
243		1	return 0;
244			}
245			}
246		8	return 1;
247			}
248
249		16	static int query_formats(AVFilterContext *ctx)
250			{
251		16	PanContext *pan = ctx->priv;
252		16	AVFilterLink *inlink = ctx->inputs[0];
253		16	AVFilterLink *outlink = ctx->outputs[0];
254		16	AVFilterFormats *formats = NULL;
255			AVFilterChannelLayouts *layouts;
256			int ret;
257
258		16	pan->pure_gains = are_gains_pure(pan);
259			/* libswr supports any sample and packing formats */
260	✗✓	16	if ((ret = ff_set_common_formats(ctx, ff_all_formats(AVMEDIA_TYPE_AUDIO))) < 0)
261			return ret;
262
263		16	formats = ff_all_samplerates();
264	✗✓	16	if ((ret = ff_set_common_samplerates(ctx, formats)) < 0)
265			return ret;
266
267			// inlink supports any channel layout
268		16	layouts = ff_all_channel_counts();
269	✗✓	16	if ((ret = ff_channel_layouts_ref(layouts, &inlink->outcfg.channel_layouts)) < 0)
270			return ret;
271
272			// outlink supports only requested output channel layout
273		16	layouts = NULL;
274	✗✓	16	if ((ret = ff_add_channel_layout(&layouts,
275	✓✓	16	pan->out_channel_layout ? pan->out_channel_layout :
276		5	FF_COUNT2LAYOUT(pan->nb_output_channels))) < 0)
277			return ret;
278		16	return ff_channel_layouts_ref(layouts, &outlink->incfg.channel_layouts);
279			}
280
281		16	static int config_props(AVFilterLink *link)
282			{
283		16	AVFilterContext *ctx = link->dst;
284		16	PanContext *pan = ctx->priv;
285			char buf[1024], *cur;
286			int i, j, k, r;
287			double t;
288
289	✓✓	16	if (pan->need_renumber) {
290			// input channels were given by their name: renumber them
291	✓✓	195	for (i = j = 0; i < MAX_CHANNELS; i++) {
292	✓✓	192	if ((link->channel_layout >> i) & 1) {
293	✓✓	25	for (k = 0; k < pan->nb_output_channels; k++)
294		16	pan->gain[k][j] = pan->gain[k][i];
295		9	j++;
296			}
297			}
298			}
299
300			// sanity check; can't be done in query_formats since the inlink
301			// channel layout is unknown at that time
302	✓✗	16	if (link->channels > MAX_CHANNELS \|\|
303	✗✓	16	pan->nb_output_channels > MAX_CHANNELS) {
304			av_log(ctx, AV_LOG_ERROR,
305			"af_pan supports a maximum of %d channels. "
306			"Feel free to ask for a higher limit.\n", MAX_CHANNELS);
307			return AVERROR_PATCHWELCOME;
308			}
309
310			// init libswresample context
311		32	pan->swr = swr_alloc_set_opts(pan->swr,
312		16	pan->out_channel_layout, link->format, link->sample_rate,
313		16	link->channel_layout, link->format, link->sample_rate,
314			0, ctx);
315	✗✓	16	if (!pan->swr)
316			return AVERROR(ENOMEM);
317	✓✓	16	if (!link->channel_layout) {
318	✗✓	3	if (av_opt_set_int(pan->swr, "ich", link->channels, 0) < 0)
319			return AVERROR(EINVAL);
320			}
321	✓✓	16	if (!pan->out_channel_layout) {
322	✗✓	5	if (av_opt_set_int(pan->swr, "och", pan->nb_output_channels, 0) < 0)
323			return AVERROR(EINVAL);
324			}
325
326			// gains are pure, init the channel mapping
327	✓✓	16	if (pan->pure_gains) {
328
329			// get channel map from the pure gains
330	✓✓	21	for (i = 0; i < pan->nb_output_channels; i++) {
331		13	int ch_id = -1;
332	✓✓	21	for (j = 0; j < link->channels; j++) {
333	✓✓	19	if (pan->gain[i][j]) {
334		11	ch_id = j;
335		11	break;
336			}
337			}
338		13	pan->channel_map[i] = ch_id;
339			}
340
341		8	av_opt_set_int(pan->swr, "icl", pan->out_channel_layout, 0);
342		8	av_opt_set_int(pan->swr, "uch", pan->nb_output_channels, 0);
343		8	swr_set_channel_mapping(pan->swr, pan->channel_map);
344			} else {
345			// renormalize
346	✓✓	35	for (i = 0; i < pan->nb_output_channels; i++) {
347	✓✓	27	if (!((pan->need_renorm >> i) & 1))
348		23	continue;
349		4	t = 0;
350	✓✓	16	for (j = 0; j < link->channels; j++)
351		12	t += fabs(pan->gain[i][j]);
352	✓✗✗✓	4	if (t > -1E-5 && t < 1E-5) {
353			// t is almost 0 but not exactly, this is probably a mistake
354			if (t)
355			av_log(ctx, AV_LOG_WARNING,
356			"Degenerate coefficients while renormalizing\n");
357			continue;
358			}
359	✓✓	16	for (j = 0; j < link->channels; j++)
360		12	pan->gain[i][j] /= t;
361			}
362		8	av_opt_set_int(pan->swr, "icl", link->channel_layout, 0);
363		8	av_opt_set_int(pan->swr, "ocl", pan->out_channel_layout, 0);
364		8	swr_set_matrix(pan->swr, pan->gain[0], pan->gain[1] - pan->gain[0]);
365			}
366
367		16	r = swr_init(pan->swr);
368	✗✓	16	if (r < 0)
369			return r;
370
371			// summary
372	✓✓	56	for (i = 0; i < pan->nb_output_channels; i++) {
373		40	cur = buf;
374	✓✓	207	for (j = 0; j < link->channels; j++) {
375	✓✓	167	r = snprintf(cur, buf + sizeof(buf) - cur, "%s%.3g i%d",
376			j ? " + " : "", pan->gain[i][j], j);
377	✓✗	167	cur += FFMIN(buf + sizeof(buf) - cur, r);
378			}
379		40	av_log(ctx, AV_LOG_VERBOSE, "o%d = %s\n", i, buf);
380			}
381			// add channel mapping summary if possible
382	✓✓	16	if (pan->pure_gains) {
383		8	av_log(ctx, AV_LOG_INFO, "Pure channel mapping detected:");
384	✓✓	21	for (i = 0; i < pan->nb_output_channels; i++)
385	✓✓	13	if (pan->channel_map[i] < 0)
386		2	av_log(ctx, AV_LOG_INFO, " M");
387			else
388		11	av_log(ctx, AV_LOG_INFO, " %d", pan->channel_map[i]);
389		8	av_log(ctx, AV_LOG_INFO, "\n");
390		8	return 0;
391			}
392		8	return 0;
393			}
394
395		2076	static int filter_frame(AVFilterLink inlink, AVFrame insamples)
396			{
397			int ret;
398		2076	int n = insamples->nb_samples;
399		2076	AVFilterLink *const outlink = inlink->dst->outputs[0];
400		2076	AVFrame *outsamples = ff_get_audio_buffer(outlink, n);
401		2076	PanContext *pan = inlink->dst->priv;
402
403	✗✓	2076	if (!outsamples) {
404			av_frame_free(&insamples);
405			return AVERROR(ENOMEM);
406			}
407		2076	swr_convert(pan->swr, outsamples->extended_data, n,
408		2076	(void *)insamples->extended_data, n);
409		2076	av_frame_copy_props(outsamples, insamples);
410		2076	outsamples->channel_layout = outlink->channel_layout;
411		2076	outsamples->channels = outlink->channels;
412
413		2076	ret = ff_filter_frame(outlink, outsamples);
414		2076	av_frame_free(&insamples);
415		2076	return ret;
416			}
417
418		16	static av_cold void uninit(AVFilterContext *ctx)
419			{
420		16	PanContext *pan = ctx->priv;
421		16	swr_free(&pan->swr);
422		16	}
423
424			#define OFFSET(x) offsetof(PanContext, x)
425
426			static const AVOption pan_options[] = {
427			{ "args", NULL, OFFSET(args), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, AV_OPT_FLAG_AUDIO_PARAM \| AV_OPT_FLAG_FILTERING_PARAM },
428			{ NULL }
429			};
430
431			AVFILTER_DEFINE_CLASS(pan);
432
433			static const AVFilterPad pan_inputs[] = {
434			{
435			.name = "default",
436			.type = AVMEDIA_TYPE_AUDIO,
437			.config_props = config_props,
438			.filter_frame = filter_frame,
439			},
440			{ NULL }
441			};
442
443			static const AVFilterPad pan_outputs[] = {
444			{
445			.name = "default",
446			.type = AVMEDIA_TYPE_AUDIO,
447			},
448			{ NULL }
449			};
450
451			AVFilter ff_af_pan = {
452			.name = "pan",
453			.description = NULL_IF_CONFIG_SMALL("Remix channels with coefficients (panning)."),
454			.priv_size = sizeof(PanContext),
455			.priv_class = &pan_class,
456			.init = init,
457			.uninit = uninit,
458			.query_formats = query_formats,
459			.inputs = pan_inputs,
460			.outputs = pan_outputs,
461			};