[FFmpeg-devel] [PATCH 5/5] amerge: accept multiple inputs.

Stefano Sabatini stefasab at gmail.com
Tue Jun 5 17:01:44 CEST 2012


On date Sunday 2012-06-03 21:44:50 +0200, Nicolas George encoded:
> 
> Signed-off-by: Nicolas George <nicolas.george at normalesup.org>
> ---
>  doc/filters.texi        |   22 +++---
>  libavfilter/af_amerge.c |  178 ++++++++++++++++++++++++++++++++---------------
>  2 files changed, 132 insertions(+), 68 deletions(-)
> 
> diff --git a/doc/filters.texi b/doc/filters.texi
> index 324a154..3aecc5e 100644
> --- a/doc/filters.texi
> +++ b/doc/filters.texi
> @@ -168,9 +168,16 @@ aformat=sample_fmts\=u8\,s16:channel_layouts\=stereo
>  
>  @section amerge
>  
> -Merge two audio streams into a single multi-channel stream.
> +Merge two audio streams or more into a single multi-channel stream.

Nit: two or more audio streams ...

sounds nicer to my Englian ears.

>  
> -This filter does not need any argument.
> +The filter accepts the following named options:
> +
> + at table @option
> +

> + at item inputs
> +Number of inputs. Default is 2.

Nit: Set the number of input.

> +
> + at end table
>  
>  If the channel layouts of the inputs are disjoint, and therefore compatible,
>  the channel layout of the output will be set accordingly and the channels
> @@ -189,7 +196,7 @@ On the other hand, if both input are in stereo, the output channels will be
>  in the default order: a1, a2, b1, b2, and the channel layout will be
>  arbitrarily set to 4.0, which may or may not be the expected value.
>  
> -Both inputs must have the same sample rate, and format.
> +All inputs must have the same sample rate, and format.
>  
>  If inputs do not have the same duration, the output will stop with the
>  shortest.
> @@ -199,8 +206,7 @@ Example: merge two mono files into a stereo stream:
>  amovie=left.wav [l] ; amovie=right.mp3 [r] ; [l] [r] amerge
>  @end example
>  
> -If you need to do multiple merges (for instance multiple mono audio streams in
> -a single video media), you can do:
> +Example: multiple merges:
>  @example
>  ffmpeg -f lavfi -i "
>  amovie=input.mkv:si=0 [a0];
> @@ -209,11 +215,7 @@ amovie=input.mkv:si=2 [a2];
>  amovie=input.mkv:si=3 [a3];
>  amovie=input.mkv:si=4 [a4];
>  amovie=input.mkv:si=5 [a5];
> -[a0][a1] amerge [x0];
> -[x0][a2] amerge [x1];
> -[x1][a3] amerge [x2];
> -[x2][a4] amerge [x3];
> -[x3][a5] amerge" -c:a pcm_s16le output.mkv
> +[a0][a1][a2][a3][a4][a5] amerge=inputs=6" -c:a pcm_s16le output.mkv
>  @end example
>  
>  @section amix
> diff --git a/libavfilter/af_amerge.c b/libavfilter/af_amerge.c
> index 394067e..364534a 100644
> --- a/libavfilter/af_amerge.c
> +++ b/libavfilter/af_amerge.c
> @@ -23,6 +23,8 @@
>   * Audio merging filter
>   */
>  

> +#include "libavutil/opt.h"
> +#include "libavutil/bprint.h"

Nit++: alphabetical order

>  #include "libswresample/swresample.h" // only for SWR_CH_MAX
>  #include "avfilter.h"
>  #include "audio.h"
> @@ -30,6 +32,8 @@
>  #include "internal.h"
>  
>  typedef struct {
> +    const AVClass *class;
> +    int nb_inputs;
>      int route[SWR_CH_MAX]; /**< channels routing, see copy_samples */
>      int bps;
>      struct amerge_input {
> @@ -37,27 +41,46 @@ typedef struct {
>          int nb_ch;         /**< number of channels for the input */
>          int nb_samples;
>          int pos;
> -    } in[2];
> +    } *in;
>  } AMergeContext;
>  
> +#define OFFSET(x) offsetof(AMergeContext, x)
> +
> +static const AVOption amerge_options[] = {
> +    { "inputs", "specify the number of inputs", OFFSET(nb_inputs),
> +      AV_OPT_TYPE_INT, { .dbl = 2 }, 2, SWR_CH_MAX },
> +};

Also maybe a short alias ("n"?) may be useful.

> +
> +static const char *amerge_get_name(void *ctx)
> +{
> +    return "amerge";
> +}
> +
> +static const AVClass amerge_class = {
> +    .class_name = "AMergeContext",
> +    .item_name  = amerge_get_name,

av_default_item_name() should be enough (and class_name = "amerge").

> +    .option     = amerge_options,
> +};
> +
>  static av_cold void uninit(AVFilterContext *ctx)
>  {
>      AMergeContext *am = ctx->priv;
>      int i;
>  
> -    for (i = 0; i < 2; i++)
> +    for (i = 0; i < am->nb_inputs; i++)
>          ff_bufqueue_discard_all(&am->in[i].queue);
> +    av_freep(&am->in);
>  }
>  
>  static int query_formats(AVFilterContext *ctx)
>  {
>      AMergeContext *am = ctx->priv;
> -    int64_t inlayout[2], outlayout;
> +    int64_t inlayout[SWR_CH_MAX], outlayout = 0;
>      AVFilterFormats *formats;
>      AVFilterChannelLayouts *layouts;
> -    int i;
> +    int i, overlap = 0, nb_ch = 0;
>  
> -    for (i = 0; i < 2; i++) {
> +    for (i = 0; i < am->nb_inputs; i++) {
>          if (!ctx->inputs[i]->in_channel_layouts ||
>              !ctx->inputs[i]->in_channel_layouts->nb_channel_layouts) {
>              av_log(ctx, AV_LOG_ERROR,
> @@ -71,33 +94,38 @@ static int query_formats(AVFilterContext *ctx)
>              av_log(ctx, AV_LOG_INFO, "Using \"%s\" for input %d\n", buf, i + 1);
>          }
>          am->in[i].nb_ch = av_get_channel_layout_nb_channels(inlayout[i]);
> +        if (outlayout & inlayout[i])
> +            overlap++;
> +        outlayout |= inlayout[i];
> +        nb_ch += am->in[i].nb_ch;
>      }
> -    if (am->in[0].nb_ch + am->in[1].nb_ch > SWR_CH_MAX) {
> +    if (nb_ch > SWR_CH_MAX) {
>          av_log(ctx, AV_LOG_ERROR, "Too many channels (max %d)\n", SWR_CH_MAX);
>          return AVERROR(EINVAL);
>      }
> -    if (inlayout[0] & inlayout[1]) {
> +    if (overlap) {
>          av_log(ctx, AV_LOG_WARNING,
>                 "Inputs overlap: output layout will be meaningless\n");
> -        for (i = 0; i < am->in[0].nb_ch + am->in[1].nb_ch; i++)
> +        for (i = 0; i < nb_ch; i++)
>              am->route[i] = i;
> -        outlayout = av_get_default_channel_layout(am->in[0].nb_ch +
> -                                                  am->in[1].nb_ch);
> +        outlayout = av_get_default_channel_layout(nb_ch);
>          if (!outlayout)
> -            outlayout = ((int64_t)1 << (am->in[0].nb_ch + am->in[1].nb_ch)) - 1;
> +            outlayout = ((int64_t)1 << nb_ch) - 1;
>      } else {
> -        int *route[2] = { am->route, am->route + am->in[0].nb_ch };
> +        int *route[SWR_CH_MAX];
>          int c, out_ch_number = 0;
>  
> -        outlayout = inlayout[0] | inlayout[1];
> +        route[0] = am->route;
> +        for (i = 1; i < am->nb_inputs; i++)
> +            route[i] = route[i - 1] + am->in[i - 1].nb_ch;
>          for (c = 0; c < 64; c++)
> -            for (i = 0; i < 2; i++)
> +            for (i = 0; i < am->nb_inputs; i++)
>                  if ((inlayout[i] >> c) & 1)
>                      *(route[i]++) = out_ch_number++;
>      }
>      formats = avfilter_make_format_list(ff_packed_sample_fmts);
>      avfilter_set_common_sample_formats(ctx, formats);
> -    for (i = 0; i < 2; i++) {
> +    for (i = 0; i < am->nb_inputs; i++) {
>          layouts = NULL;
>          ff_add_channel_layout(&layouts, inlayout[i]);
>          ff_channel_layouts_ref(layouts, &ctx->inputs[i]->out_channel_layouts);
> @@ -113,26 +141,31 @@ static int config_output(AVFilterLink *outlink)
>  {
>      AVFilterContext *ctx = outlink->src;
>      AMergeContext *am = ctx->priv;
> -    int64_t layout;
> -    char name[3][256];
> +    AVBPrint bp;
>      int i;
>  
> -    if (ctx->inputs[0]->sample_rate != ctx->inputs[1]->sample_rate) {
> -        av_log(ctx, AV_LOG_ERROR,
> -               "Inputs must have the same sample rate "
> -               "(%"PRIi64" vs %"PRIi64")\n",
> -               ctx->inputs[0]->sample_rate, ctx->inputs[1]->sample_rate);
> -        return AVERROR(EINVAL);
> +    for (i = 1; i < am->nb_inputs; i++) {
> +        if (ctx->inputs[i]->sample_rate != ctx->inputs[0]->sample_rate) {
> +            av_log(ctx, AV_LOG_ERROR,
> +                   "Inputs must have the same sample rate "
> +                   "(%"PRIi64" for in%d vs %"PRIi64")\n",
> +                   ctx->inputs[i]->sample_rate, i, ctx->inputs[0]->sample_rate);
> +            return AVERROR(EINVAL);
> +        }
>      }
>      am->bps = av_get_bytes_per_sample(ctx->outputs[0]->format);
>      outlink->sample_rate = ctx->inputs[0]->sample_rate;
>      outlink->time_base   = ctx->inputs[0]->time_base;
> -    for (i = 0; i < 3; i++) {
> -        layout = (i < 2 ? ctx->inputs[i] : ctx->outputs[0])->channel_layout;
> -        av_get_channel_layout_string(name[i], sizeof(name[i]), -1, layout);
> +
> +    av_bprint_init(&bp, 0, 1);
> +    for (i = 0; i < am->nb_inputs; i++) {
> +        av_bprintf(&bp, "%sin%d:", i ? " + " : "", i);
> +        av_bprint_channel_layout(&bp, -1, ctx->inputs[i]->channel_layout);
>      }
> -    av_log(ctx, AV_LOG_INFO,
> -           "in1:%s + in2:%s -> out:%s\n", name[0], name[1], name[2]);
> +    av_bprintf(&bp, " -> out:");
> +    av_bprint_channel_layout(&bp, -1, ctx->outputs[0]->channel_layout);
> +    av_log(ctx, AV_LOG_INFO, "%s\n", bp.str);
> +
>      return 0;
>  }
>  
> @@ -142,7 +175,7 @@ static int request_frame(AVFilterLink *outlink)
>      AMergeContext *am = ctx->priv;
>      int i, ret;
>  
> -    for (i = 0; i < 2; i++)
> +    for (i = 0; i < am->nb_inputs; i++)
>          if (!am->in[i].nb_samples)
>              if ((ret = avfilter_request_frame(ctx->inputs[i])) < 0)
>                  return ret;
> @@ -150,7 +183,8 @@ static int request_frame(AVFilterLink *outlink)
>  }
>  
>  /**
> - * Copy samples from two input streams to one output stream.
> + * Copy samples from several input streams to one output stream.
> + * @param nb_inputs number of inputs
>   * @param in        inputs; used only for the nb_ch field;
>   * @param route     routing values;
>   *                  input channel i goes to output channel route[i];
> @@ -164,21 +198,24 @@ static int request_frame(AVFilterLink *outlink)
>   * @param ns        number of samples to copy
>   * @param bps       bytes per sample
>   */
> -static inline void copy_samples(struct amerge_input in[2], int *route, uint8_t *ins[2],
> +static inline void copy_samples(int nb_inputs, struct amerge_input in[],
> +                                int *route, uint8_t *ins[],
>                                  uint8_t **outs, int ns, int bps)
>  {
>      int *route_cur;
> -    int i, c;
> +    int i, c, nb_ch = 0;
>  
> +    for (i = 0; i < nb_inputs; i++)
> +        nb_ch += in[i].nb_ch;
>      while (ns--) {
>          route_cur = route;
> -        for (i = 0; i < 2; i++) {
> +        for (i = 0; i < nb_inputs; i++) {
>              for (c = 0; c < in[i].nb_ch; c++) {
>                  memcpy((*outs) + bps * *(route_cur++), ins[i], bps);
>                  ins[i] += bps;
>              }
>          }
> -        *outs += (in[0].nb_ch + in[1].nb_ch) * bps;
> +        *outs += nb_ch * bps;
>      }
>  }
>  
> @@ -187,21 +224,26 @@ static void filter_samples(AVFilterLink *inlink, AVFilterBufferRef *insamples)
>      AVFilterContext *ctx = inlink->dst;
>      AMergeContext *am = ctx->priv;
>      AVFilterLink *const outlink = ctx->outputs[0];
> -    int input_number = inlink == ctx->inputs[1];
> +    int input_number;
>      int nb_samples, ns, i;
> -    AVFilterBufferRef *outbuf, *inbuf[2];
> -    uint8_t *ins[2], *outs;
> +    AVFilterBufferRef *outbuf, *inbuf[SWR_CH_MAX];
> +    uint8_t *ins[SWR_CH_MAX], *outs;
>  
> +    for (input_number = 0; input_number < am->nb_inputs; input_number++)
> +        if (inlink == ctx->inputs[input_number])
> +            break;
> +    av_assert1(input_number < am->nb_inputs);
>      ff_bufqueue_add(ctx, &am->in[input_number].queue, insamples);
>      am->in[input_number].nb_samples += insamples->audio->nb_samples;
> -    if (!am->in[!input_number].nb_samples)
> +    nb_samples = am->in[0].nb_samples;
> +    for (i = 1; i < am->nb_inputs; i++)
> +        nb_samples = FFMIN(nb_samples, am->in[i].nb_samples);
> +    if (!nb_samples)
>          return;
>  
> -    nb_samples = FFMIN(am->in[0].nb_samples,
> -                       am->in[1].nb_samples);
>      outbuf = ff_get_audio_buffer(ctx->outputs[0], AV_PERM_WRITE, nb_samples);
>      outs = outbuf->data[0];
> -    for (i = 0; i < 2; i++) {
> +    for (i = 0; i < am->nb_inputs; i++) {
>          inbuf[i] = ff_bufqueue_peek(&am->in[i].queue, 0);
>          ins[i] = inbuf[i]->data[0] +
>                   am->in[i].pos * am->in[i].nb_ch * am->bps;
> @@ -218,27 +260,27 @@ static void filter_samples(AVFilterLink *inlink, AVFilterBufferRef *insamples)
>  
>      while (nb_samples) {
>          ns = nb_samples;
> -        for (i = 0; i < 2; i++)
> +        for (i = 0; i < am->nb_inputs; i++)
>              ns = FFMIN(ns, inbuf[i]->audio->nb_samples - am->in[i].pos);
>          /* Unroll the most common sample formats: speed +~350% for the loop,
>             +~13% overall (including two common decoders) */
>          switch (am->bps) {
>              case 1:
> -                copy_samples(am->in, am->route, ins, &outs, ns, 1);
> +                copy_samples(am->nb_inputs, am->in, am->route, ins, &outs, ns, 1);
>                  break;
>              case 2:
> -                copy_samples(am->in, am->route, ins, &outs, ns, 2);
> +                copy_samples(am->nb_inputs, am->in, am->route, ins, &outs, ns, 2);
>                  break;
>              case 4:
> -                copy_samples(am->in, am->route, ins, &outs, ns, 4);
> +                copy_samples(am->nb_inputs, am->in, am->route, ins, &outs, ns, 4);
>                  break;
>              default:
> -                copy_samples(am->in, am->route, ins, &outs, ns, am->bps);
> +                copy_samples(am->nb_inputs, am->in, am->route, ins, &outs, ns, am->bps);
>                  break;
>          }
>  
>          nb_samples -= ns;
> -        for (i = 0; i < 2; i++) {
> +        for (i = 0; i < am->nb_inputs; i++) {
>              am->in[i].nb_samples -= ns;
>              am->in[i].pos += ns;
>              if (am->in[i].pos == inbuf[i]->audio->nb_samples) {
> @@ -253,25 +295,45 @@ static void filter_samples(AVFilterLink *inlink, AVFilterBufferRef *insamples)
>      ff_filter_samples(ctx->outputs[0], outbuf);
>  }
>  
> +static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
> +{
> +    AMergeContext *am = ctx->priv;
> +    int ret, i;
> +    char name[16];
> +
> +    am->class = &amerge_class;
> +    av_opt_set_defaults(am);
> +    ret = av_set_options_string(am, args, "=", ":");
> +    if (ret < 0) {
> +        av_log(ctx, AV_LOG_ERROR, "Error parsing options: '%s'\n", args);
> +        return ret;
> +    }
> +    am->in = av_calloc(am->nb_inputs, sizeof(*am->in));
> +    if (!am->in)
> +        return AVERROR(ENOMEM);

> +    for (i = 0; i < am->nb_inputs; i++) {
> +        AVFilterPad pad = {
> +            .name             = name,
> +            .type             = AVMEDIA_TYPE_AUDIO,
> +            .filter_samples   = filter_samples,
> +            .min_perms        = AV_PERM_READ | AV_PERM_PRESERVE,
> +        };
> +        snprintf(name, sizeof(name), "in%d", i);
> +        avfilter_insert_inpad(ctx, i, &pad);

Uhm... is this really working? Shouldn't you strdup the name?

[...]
-- 
FFmpeg = Fanciful & Fierce Magical Purposeless Everlasting Governor


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