[FFmpeg-devel] [PATCH v9 3/3][GSOC] avformat/tee: Handling slave failure in tee muxer

Nicolas George george at nsup.org
Wed Apr 20 15:31:07 CEST 2016


Le decadi 30 germinal, an CCXXIV, sebechlebskyjan at gmail.com a écrit :
> From: Jan Sebechlebsky <sebechlebskyjan at gmail.com>
> 
> Adds per slave option 'onfail' to the tee muxer allowing an output to
> fail,so other slave outputs can continue.
> 
> Signed-off-by: Jan Sebechlebsky <sebechlebskyjan at gmail.com>
> ---
>  This is embarassing, sorry for that! You're right in both, I've tried 
>  to merge my old file with the changes in previous patch and it obviosly
>  didn't end well. Next time I'll try to edit it manually to notice such 
>  mistakes.
> 
>  Hopefully, this patch will be final.
> 
>  Regards,
>  Jan S.
> 
>  doc/muxers.texi   | 14 +++++++++
>  libavformat/tee.c | 92 ++++++++++++++++++++++++++++++++++++++++++++++++-------
>  2 files changed, 95 insertions(+), 11 deletions(-)
> 
> diff --git a/doc/muxers.texi b/doc/muxers.texi
> index 042efce..c62d4b5 100644
> --- a/doc/muxers.texi
> +++ b/doc/muxers.texi
> @@ -1453,6 +1453,12 @@ Select the streams that should be mapped to the slave output,
>  specified by a stream specifier. If not specified, this defaults to
>  all the input streams. You may use multiple stream specifiers
>  separated by commas (@code{,}) e.g.: @code{a:0,v}
> +
> + at item onfail
> +Specify behaviour on output failure. This can be set to either @code{abort} (which is
> +default) or @code{ignore}. @code{abort} will cause whole process to fail in case of failure
> +on this slave output. @code{ignore} will ignore failure on this output, so other outputs
> +will continue without being affected.
>  @end table
>  
>  @subsection Examples
> @@ -1467,6 +1473,14 @@ ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
>  @end example
>  
>  @item
> +As above, but continue streaming even if output to local file fails
> +(for example local drive fills up):
> + at example
> +ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
> +  "[onfail=ignore]archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
> + at end example
> +
> + at item
>  Use @command{ffmpeg} to encode the input, and send the output
>  to three different destinations. The @code{dump_extra} bitstream
>  filter is used to add extradata information to all the output video
> diff --git a/libavformat/tee.c b/libavformat/tee.c
> index 753f7ea..ca74cb1 100644
> --- a/libavformat/tee.c
> +++ b/libavformat/tee.c
> @@ -29,10 +29,19 @@
>  
>  #define MAX_SLAVES 16
>  
> +typedef enum {
> +    ON_SLAVE_FAILURE_ABORT  = 1,
> +    ON_SLAVE_FAILURE_IGNORE = 2
> +} SlaveFailurePolicy;
> +
> +#define DEFAULT_SLAVE_FAILURE_POLICY ON_SLAVE_FAILURE_ABORT
> +
>  typedef struct {
>      AVFormatContext *avf;
>      AVBitStreamFilterContext **bsfs; ///< bitstream filters per stream
>  
> +    SlaveFailurePolicy on_fail;
> +
>      /** map from input to output streams indexes,
>       * disabled output streams are set to -1 */
>      int *stream_map;
> @@ -42,6 +51,7 @@ typedef struct {
>  typedef struct TeeContext {
>      const AVClass *class;
>      unsigned nb_slaves;
> +    unsigned nb_alive;
>      TeeSlave slaves[MAX_SLAVES];
>  } TeeContext;
>  
> @@ -136,6 +146,23 @@ end:
>      return ret;
>  }
>  
> +static inline int parse_slave_failure_policy_option(const char *opt, TeeSlave *tee_slave)
> +{
> +    if (!opt) {
> +        tee_slave->on_fail = DEFAULT_SLAVE_FAILURE_POLICY;
> +        return 0;
> +    } else if (!av_strcasecmp("abort", opt)) {
> +        tee_slave->on_fail = ON_SLAVE_FAILURE_ABORT;
> +        return 0;
> +    } else if (!av_strcasecmp("ignore", opt)) {
> +        tee_slave->on_fail = ON_SLAVE_FAILURE_IGNORE;
> +        return 0;
> +    }
> +    /* Set failure behaviour to abort, so invalid option error will not be ignored */
> +    tee_slave->on_fail = ON_SLAVE_FAILURE_ABORT;
> +    return AVERROR(EINVAL);
> +}
> +
>  static int close_slave(TeeSlave *tee_slave)
>  {
>      AVFormatContext *avf;
> @@ -184,7 +211,7 @@ static int open_slave(AVFormatContext *avf, char *slave, TeeSlave *tee_slave)
>      AVDictionary *options = NULL;
>      AVDictionaryEntry *entry;
>      char *filename;
> -    char *format = NULL, *select = NULL;
> +    char *format = NULL, *select = NULL, *on_fail = NULL;
>      AVFormatContext *avf2 = NULL;
>      AVStream *st, *st2;
>      int stream_count;
> @@ -204,6 +231,14 @@ static int open_slave(AVFormatContext *avf, char *slave, TeeSlave *tee_slave)
>  
>      STEAL_OPTION("f", format);
>      STEAL_OPTION("select", select);
> +    STEAL_OPTION("onfail", on_fail);
> +
> +    ret = parse_slave_failure_policy_option(on_fail, tee_slave);
> +    if (ret < 0) {
> +        av_log(avf, AV_LOG_ERROR,
> +               "Invalid onfail option value, valid options are 'abort' and 'ignore'\n");
> +        goto end;
> +    }
>  
>      ret = avformat_alloc_output_context2(&avf2, NULL, format, filename);
>      if (ret < 0)
> @@ -351,6 +386,7 @@ static int open_slave(AVFormatContext *avf, char *slave, TeeSlave *tee_slave)
>  end:
>      av_free(format);
>      av_free(select);
> +    av_free(on_fail);
>      av_dict_free(&options);
>      av_freep(&tmp_select);
>      return ret;
> @@ -380,6 +416,28 @@ static void log_slave(TeeSlave *slave, void *log_ctx, int log_level)
>      }
>  }
>  
> +static int tee_process_slave_failure(AVFormatContext *avf, unsigned slave_idx, int err_n)
> +{
> +    TeeContext *tee = avf->priv_data;
> +    TeeSlave *tee_slave = &tee->slaves[slave_idx];
> +
> +    tee->nb_alive--;
> +
> +    close_slave(tee_slave);
> +
> +    if (!tee->nb_alive) {
> +        av_log(avf, AV_LOG_ERROR, "All tee outputs failed.\n");
> +        return err_n;
> +    } else if (tee_slave->on_fail == ON_SLAVE_FAILURE_ABORT) {
> +        av_log(avf, AV_LOG_ERROR, "Slave muxer #%u failed, aborting.\n", slave_idx);
> +        return err_n;
> +    } else {

> +        av_log(avf, AV_LOG_ERROR, "Slave muxer #%u failed, continuing with %u/%u slaves.\n",
> +               slave_idx, tee->nb_alive, tee->nb_slaves);

This is minor: it would probably be a good idea to print the error message
here, since the error is being ignored afterwards.

> +        return 0;
> +    }
> +}
> +
>  static int tee_write_header(AVFormatContext *avf)
>  {
>      TeeContext *tee = avf->priv_data;
> @@ -403,19 +461,24 @@ static int tee_write_header(AVFormatContext *avf)
>              filename++;
>      }
>  
> -    tee->nb_slaves = nb_slaves;
> +    tee->nb_slaves = tee->nb_alive = nb_slaves;
>  
>      for (i = 0; i < nb_slaves; i++) {
> -        if ((ret = open_slave(avf, slaves[i], &tee->slaves[i])) < 0)
> -            goto fail;
> -        log_slave(&tee->slaves[i], avf, AV_LOG_VERBOSE);
> +        if ((ret = open_slave(avf, slaves[i], &tee->slaves[i])) < 0) {
> +            ret = tee_process_slave_failure(avf, i, ret);
> +            if (ret < 0)
> +                goto fail;
> +        } else {
> +            log_slave(&tee->slaves[i], avf, AV_LOG_VERBOSE);
> +        }
>          av_freep(&slaves[i]);
>      }
>  
>      for (i = 0; i < avf->nb_streams; i++) {
>          int j, mapped = 0;
>          for (j = 0; j < tee->nb_slaves; j++)
> -            mapped += tee->slaves[j].stream_map[i] >= 0;
> +            if (tee->slaves[j].avf)
> +                mapped += tee->slaves[j].stream_map[i] >= 0;
>          if (!mapped)
>              av_log(avf, AV_LOG_WARNING, "Input stream #%d is not mapped "
>                     "to any slave.\n", i);
> @@ -432,13 +495,16 @@ fail:
>  static int tee_write_trailer(AVFormatContext *avf)
>  {
>      TeeContext *tee = avf->priv_data;
> +    AVFormatContext *avf2;
>      int ret_all = 0, ret;
>      unsigned i;
>  
>      for (i = 0; i < tee->nb_slaves; i++) {
> -        if ((ret = close_slave(&tee->slaves[i])) < 0)
> -            if (!ret_all)
> +        if ((ret = close_slave(&tee->slaves[i])) < 0) {
> +            ret = tee_process_slave_failure(avf, i, ret);
> +            if (!ret_all && ret < 0)
>                  ret_all = ret;
> +        }
>      }
>      return ret_all;
>  }
> @@ -454,7 +520,9 @@ static int tee_write_packet(AVFormatContext *avf, AVPacket *pkt)
>      AVRational tb, tb2;
>  
>      for (i = 0; i < tee->nb_slaves; i++) {
> -        avf2 = tee->slaves[i].avf;
> +        if (!(avf2 = tee->slaves[i].avf))
> +            continue;
> +
>          s = pkt->stream_index;
>          s2 = tee->slaves[i].stream_map[s];
>          if (s2 < 0)
> @@ -475,9 +543,11 @@ static int tee_write_packet(AVFormatContext *avf, AVPacket *pkt)
>  
>          if ((ret = av_apply_bitstream_filters(avf2->streams[s2]->codec, &pkt2,
>                                                tee->slaves[i].bsfs[s2])) < 0 ||
> -            (ret = av_interleaved_write_frame(avf2, &pkt2)) < 0)
> -            if (!ret_all)
> +            (ret = av_interleaved_write_frame(avf2, &pkt2)) < 0) {
> +            ret = tee_process_slave_failure(avf, i, ret);
> +            if (!ret_all && ret < 0)
>                  ret_all = ret;
> +        }
>      }
>      return ret_all;
>  }

Apart from the above comment, I see nothing wrong with the patch.

Regards,

-- 
  Nicolas George
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: Digital signature
URL: <http://ffmpeg.org/pipermail/ffmpeg-devel/attachments/20160420/c6fd1842/attachment.sig>


More information about the ffmpeg-devel mailing list