[vlc-devel] [PATCH] opus: add opus encoder

Denis Charmet typx at dinauz.org
Tue Sep 17 10:59:20 CEST 2013


Hi,

Le lundi 16 septembre 2013 à 11:52:47, Tristan Matthews a écrit :
> +{
> +    encoder_sys_t *p_sys = enc->p_sys;
> +    const unsigned channels = enc->fmt_out.audio.i_channels;
> +    const float *src_buf = ((const float *) src->p_buffer) + src_start;
> +    float *dest_buf = p_sys->buffer + (p_sys->i_nb_samples * channels);
> +    const unsigned end = samples * channels;
> +
> +    for (unsigned i = 0; i < end; ++i)
> +        dest_buf[i] = src_buf[i];
memcpy?
> +static block_t *Encode(encoder_t *enc, block_t *buf)
> +{
> +    encoder_sys_t *sys = enc->p_sys;
> +    opus_int32 bytes_encoded;
> +
> +    if (!buf)
> +        return NULL;
> +
> +    mtime_t i_pts = buf->i_pts -
> +                (mtime_t) CLOCK_FREQ * (mtime_t) sys->i_samples_delay /
> +                (mtime_t) enc->fmt_in.audio.i_rate;
> +
> +    sys->i_samples_delay += buf->i_nb_samples;
> +
> +    block_t *result = 0;
> +    unsigned src_start = 0;
> +    unsigned padding_start = 0;
> +
> +    while (sys->i_nb_samples + buf->i_nb_samples >= OPUS_FRAME_SIZE) {
Usual coding style give brackets their own line :)
> +
> +        block_t *out_block = block_Alloc(1276);
Maybe a const/define or comment to explain this value.
> +
> +        // add padding to beginning
> +        if (sys->padding) {
> +            const size_t leftover_space = OPUS_FRAME_SIZE - sys->i_nb_samples;
> +            padding_start = fill_buffer(enc, padding_start, sys->padding,
> +                    __MIN(sys->padding->i_nb_samples, leftover_space));
> +            if (sys->padding->i_nb_samples <= 0) {
> +                block_Release(sys->padding);
> +                sys->padding = 0;
> +            }
> +        }
> +
> +        if (!sys->padding) {
use else
> +            const size_t leftover_space = OPUS_FRAME_SIZE - sys->i_nb_samples;
> +            src_start = fill_buffer(enc, src_start, buf,
> +                    __MIN(buf->i_nb_samples, leftover_space));
> +        }
> +        // TODO: integer pcm
> +        bytes_encoded = opus_multistream_encode_float(sys->enc, sys->buffer,
> +                OPUS_FRAME_SIZE, out_block->p_buffer, out_block->i_buffer);
> +
> +        out_block->i_length = (mtime_t) CLOCK_FREQ *
> +            (mtime_t) OPUS_FRAME_SIZE / (mtime_t) enc->fmt_in.audio.i_rate;
> +
> +        out_block->i_dts = out_block->i_pts = i_pts;
> +
> +        sys->i_samples_delay -= OPUS_FRAME_SIZE;
> +
> +        i_pts += out_block->i_length;
> +
> +        sys->i_nb_samples = 0;
> +
> +        if (bytes_encoded < 0) {
> +            block_Release(out_block);
> +            result = NULL;
what happens to result if block_ChainAppend occured before but this
specific encoding failed?
> +        } else {
> +            out_block->i_buffer = bytes_encoded;
> +            block_ChainAppend(&result, out_block);
> +        }
> +    }
> +
> +    // put leftover samples at beginning of buffer
> +    if (buf->i_nb_samples > 0)
> +        fill_buffer(enc, src_start, buf, buf->i_nb_samples);
> +
> +    return result;
> +}
> +
> +static int OpenEncoder(vlc_object_t *p_this)
> +{
> +    encoder_t *enc = (encoder_t *)p_this;
> +
> +    if (enc->fmt_out.i_codec != VLC_CODEC_OPUS)
> +        return VLC_EGENERIC;
> +
> +    encoder_sys_t *sys = malloc(sizeof(*sys));
> +    if (!sys)
> +        return VLC_ENOMEM;
> +
> +    enc->pf_encode_audio = Encode;
> +    enc->fmt_in.i_codec = VLC_CODEC_FL32; // ?
> +    enc->fmt_in.audio.i_rate = /* Only 48kHz */
> +    enc->fmt_out.audio.i_rate = 48000;
> +    enc->fmt_out.audio.i_channels = enc->fmt_in.audio.i_channels;
> +
> +    static const char *const options[] = {
> +        NULL,
> +    };
> +    config_ChainParse(enc, "sout-opus-", options, enc->p_cfg);
Is that necessary if you don't have any options?
> +
> +    int force_narrow = 0;
> +    OpusHeader header;
> +
> +    unsigned char mapping[256];
> +    if (opus_prepare_header(enc->fmt_out.audio.i_channels,
> +            enc->fmt_out.audio.i_rate,
> +            &force_narrow,
> +            &header,
> +            mapping)) {
> +        msg_Err(enc, "Failed to prepare header.");
memleak
> +        return VLC_ENOMEM;
> +    }
> +
> +    int err;
> +    sys->enc = opus_multistream_encoder_create(enc->fmt_in.audio.i_rate,
> +            enc->fmt_in.audio.i_channels, header.nb_streams, header.nb_coupled,
> +            mapping, OPUS_APPLICATION_AUDIO, &err);
> +
> +    if (err != OPUS_OK) {
> +        msg_Err(enc, "Could not create encoder: error %d", err);
> +        free(sys);
> +        return VLC_EGENERIC;
> +    }
> +
> +   if (force_narrow != 0) {
> +        for(int i = 0; i < header.nb_streams; i++) {
> +            if (force_narrow & (1 << i)) {
> +                OpusEncoder *oe;
> +                opus_multistream_encoder_ctl(sys->enc,
> +                        OPUS_MULTISTREAM_GET_ENCODER_STATE(i, &oe));
> +                int ret = opus_encoder_ctl(oe,
> +                        OPUS_SET_MAX_BANDWIDTH(OPUS_BANDWIDTH_NARROWBAND));
> +                if (ret != OPUS_OK) {
> +                    msg_Err(enc, "OPUS_SET_MAX_BANDWIDTH on stream %d "
> +                                 "returned: %s\n", i, opus_strerror(ret));
memleak
> +                    return VLC_EGENERIC;
> +                }
> +            }
> +        }
> +    }
> +
> +    // TODO: vbr, bitrate, fec, ..
> +
> +    // Buffer for incoming audio, since opus only accepts frame sizes that are
> +    // multiples of 2.5ms
> +    enc->p_sys = sys;
> +    sys->buffer = (float *) malloc(OPUS_FRAME_SIZE * header.channels *
> +                                   sizeof(float));
> +    if (!sys->buffer)
memleak
> +        return VLC_ENOMEM;
> +
> +    sys->i_nb_samples = 0;
> +
> +    sys->i_samples_delay = 0;
> +    int ret = opus_multistream_encoder_ctl(enc->p_sys->enc,
> +            OPUS_GET_LOOKAHEAD(&sys->i_samples_delay));
> +    if (ret != OPUS_OK)
> +        msg_Err(enc, "Unable to get number of lookahead samples: %s\n",
> +                opus_strerror(ret));
> +
> +    header.preskip = sys->i_samples_delay;
> +
> +    /* Now that we have preskip, we can write the header to extradata */
> +    if (opus_write_header((uint8_t **) &enc->fmt_out.p_extra,
> +                          &enc->fmt_out.i_extra, &header)) {
> +        msg_Err(enc, "Failed to write header.");
memleak
> +        return VLC_ENOMEM;
> +    }
> +
> +    if (sys->i_samples_delay > 0) {
> +        const unsigned padding_samples = sys->i_samples_delay *
> +            enc->fmt_out.audio.i_channels;
> +        sys->padding = block_Alloc(padding_samples * sizeof(float));
> +        if (!sys->padding)
memleak
> +            return VLC_ENOMEM;
> +        sys->padding->i_nb_samples = sys->i_samples_delay;
> +        float *pad_ptr = (float *) sys->padding->p_buffer;
> +        for (unsigned i = 0; i < padding_samples; ++i)
> +            pad_ptr[i] = 0.0f;
memset?
> +    } else {
> +        sys->padding = 0;
> +    }
> +
> +    return VLC_SUCCESS;
> +}
> +
> +static void CloseEncoder(vlc_object_t *p_this)
> +{
> +    encoder_t *enc = (encoder_t *)p_this;
> +    encoder_sys_t *sys = enc->p_sys;
> +
> +    opus_multistream_encoder_destroy(sys->enc);
what about sys->padding?
> +    free(sys->buffer);
> +    free(sys);
> +}
> +#endif /* ENABLE_SOUT */
> diff --git a/modules/codec/opus_header.c b/modules/codec/opus_header.c
> index cb5fb93..3c16d0d 100644
> --- a/modules/codec/opus_header.c
> +++ b/modules/codec/opus_header.c
> @@ -30,8 +30,13 @@
>  #endif
>  
>  #include "opus_header.h"
> +#include <opus.h>
>  #include <string.h>
>  #include <stdio.h>
> +#include <stdlib.h>
> +
> +#include <vlc_common.h>
> +#include "../demux/xiph.h"
>  
>  /* Header contents:
>    - "OpusHead" (64 bits)
> @@ -213,6 +218,158 @@ int opus_header_parse(const unsigned char *packet, int len, OpusHeader *h)
>      return 1;
>  }
>  
> +#define readint(buf, base) (((buf[base+3]<<24)&0xff000000)| \
> +                           ((buf[base+2]<<16)&0xff0000)| \
> +                           ((buf[base+1]<<8)&0xff00)| \
> +                           (buf[base]&0xff))
> +#define writeint(buf, base, val) do{ buf[base+3]=((val)>>24)&0xff; \
> +                                     buf[base+2]=((val)>>16)&0xff; \
> +                                     buf[base+1]=((val)>>8)&0xff; \
> +                                     buf[base]=(val)&0xff; \
> +                                 }while(0)
> +#define writeshort(buf, base, val) do{ buf[base+1]=((val)>>8)&0xff; \
> +                                       buf[base]=(val)&0xff; \
> +                                 }while(0)
> +
You are assuming little endian running host what about a big endian?
(yes it is rare but still).

> +/*
> + Comments will be stored in the Vorbis style.
> + It is describled in the "Structure" section of
> +    http://www.xiph.org/ogg/vorbis/doc/v-comment.html
> +
> + However, Opus and other non-vorbis formats omit the "framing_bit".
> +
> +The comment header is decoded as follows:
> +  1) [vendor_length] = read an unsigned integer of 32 bits
> +  2) [vendor_string] = read a UTF-8 vector as [vendor_length] octets
> +  3) [user_comment_list_length] = read an unsigned integer of 32 bits
> +  4) iterate [user_comment_list_length] times {
> +     5) [length] = read an unsigned integer of 32 bits
> +     6) this iteration's user comment = read a UTF-8 vector as [length] octets
> +     }
> +  7) done.
> +*/
> +
> +static int comment_init(char **comments, int* length, const char *vendor_string)
> +{
> +    /*The 'vendor' field should be the actual encoding library used.*/
> +    int vendor_length = strlen(vendor_string);
> +    int user_comment_list_length = 0;
> +    int len = 8 + 4 + vendor_length + 4;
> +    char *p = (char *) malloc(len);
> +    if (p == NULL)
> +        return 1;
> +
> +    memcpy(p, "OpusTags", 8);
> +    writeint(p, 8, vendor_length);
> +    memcpy(p + 12, vendor_string, vendor_length);
> +    writeint(p, 12 + vendor_length, user_comment_list_length);
> +    *length = len;
> +    *comments = p;
> +    return 0;
> +}
> +
> +static int comment_add(char **comments, int* length, const char *tag, const char *val)
> +{
> +    char *p = *comments;
> +    int vendor_length = readint(p, 8);
> +    int user_comment_list_length = readint(p, 8 + 4 + vendor_length);
> +    int tag_len = (tag ? strlen(tag) : 0);
> +    int val_len = strlen(val);
> +    int len=(*length) + 4 + tag_len + val_len;
> +
> +    p = (char*) realloc(p, len);
> +    if (p == NULL)
> +        return 1;
> +
> +    writeint(p, *length, tag_len + val_len);          /* length of comment */
> +    if (tag) memcpy(p + *length + 4, tag, tag_len);   /* comment */
> +    memcpy(p + *length + 4 + tag_len, val, val_len);        /* comment */
> +    writeint(p, 8 + 4 + vendor_length, user_comment_list_length + 1);
> +    *comments = p;
> +    *length = len;
> +    return 0;
> +}
> +
> +int opus_prepare_header(unsigned channels, unsigned rate, int *force_narrow,
> +                        OpusHeader *header, unsigned char mapping[256])
> +{
> +    header->version = 1;
> +    header->channels = channels;
> +    header->nb_streams = header->channels;
> +    header->nb_coupled = 0;
> +    header->input_sample_rate = rate;
> +    header->gain = 0; // 0dB
> +
> +    for (size_t i = 0; i < 256; i++)
> +        mapping[i] = i;
> +
> +    if (header->channels <= 8) {
> +        static const unsigned char opusenc_streams[8][10] = {
> +            /*Coupled, NB_bitmap, mapping...*/
> +            /*1*/ {0,   0, 0},
> +            /*2*/ {1,   0, 0,1},
> +            /*3*/ {1,   0, 0,2,1},
> +            /*4*/ {2,   0, 0,1,2,3},
> +            /*5*/ {2,   0, 0,4,1,2,3},
> +            /*6*/ {2,1<<3, 0,4,1,2,3,5},
> +            /*7*/ {2,1<<4, 0,4,1,2,3,5,6},
> +            /*6*/ {3,1<<4, 0,6,1,2,3,4,5,7}
> +        };
> +        for (int i=0; i < header->channels; i++)
> +            mapping[i] = opusenc_streams[header->channels - 1][i + 2];
> +        *force_narrow = opusenc_streams[header->channels - 1][1];
> +        header->nb_coupled = opusenc_streams[header->channels - 1][0];
> +        header->nb_streams = header->channels - header->nb_coupled;
> +    }
> +    header->channel_mapping = header->channels > 8 ? 255 : header->nb_streams > 1;
> +    if (header->channel_mapping > 0)
> +        for(int i = 0; i < header->channels; i++)
> +            header->stream_map[i] = mapping[i];
memcpy?
> +
> +    return 0;
> +}
> +
> +int opus_write_header(uint8_t **p_extra, int *i_extra, OpusHeader *header)
> +{
> +    unsigned char header_data[100];
> +    const int packet_size = opus_header_to_packet(header, header_data, sizeof(header_data));
> +    ogg_packet headers[2];
> +    headers[0].packet = header_data;
> +    headers[0].bytes = packet_size;
> +    headers[0].b_o_s = 1;
> +    headers[0].e_o_s = 0;
> +    headers[0].granulepos = 0;
> +    headers[0].packetno = 0;
> +
> +    const char *opus_version = opus_get_version_string();
Is that an allocated string? if yes don't you need a free?
> +    int comments_length;
> +    char *comments;
> +    if (comment_init(&comments, &comments_length, opus_version))
> +        return 1;
> +    if (comment_add(&comments, &comments_length, "ENCODER=", "opus encoder from VLC media player"))
> +        return 1;
> +
> +    headers[1].packet = (unsigned char *) comments;
> +    headers[1].bytes = comments_length;
> +    headers[1].b_o_s = 0;
> +    headers[1].e_o_s = 0;
> +    headers[1].granulepos = 0;
> +    headers[1].packetno = 1;
> +
> +    for (unsigned i = 0; i < ARRAY_SIZE(headers); ++i) {
> +        if (xiph_AppendHeaders(i_extra, (void **) p_extra,
> +                               headers[i].bytes, headers[i].packet)) {
> +            *i_extra = 0;
> +            *p_extra = NULL;
> +        }
> +    }
> +
> +    return 0;
> +}
> +
> +#undef writeint
> +#undef writeshort
> +
>  int opus_header_to_packet(const OpusHeader *h, unsigned char *packet, int len)
>  {
>      Packet p;
> diff --git a/modules/codec/opus_header.h b/modules/codec/opus_header.h
> index 633c2f4..f7b6a7d 100644
> --- a/modules/codec/opus_header.h
> +++ b/modules/codec/opus_header.h
> @@ -45,5 +45,8 @@ typedef struct {
>  
>  int opus_header_parse(const unsigned char *header, int len, OpusHeader *h);
>  int opus_header_to_packet(const OpusHeader *h, unsigned char *packet, int len);
> +int opus_prepare_header(unsigned channels, unsigned rate, int *force_narrow,
> +                        OpusHeader *header, unsigned char mapping[256]);
> +int opus_write_header(uint8_t **p_extra, int *i_extra, OpusHeader *header);
>  
>  #endif
> diff --git a/modules/mux/ogg.c b/modules/mux/ogg.c
> index 99252b0..a805996 100644
> --- a/modules/mux/ogg.c
> +++ b/modules/mux/ogg.c
> @@ -361,6 +361,10 @@ static int AddStream( sout_mux_t *p_mux, sout_input_t *p_input )
>      case AUDIO_ES:
>          switch( p_stream->i_fourcc )
>          {
> +        case VLC_CODEC_OPUS:
> +            msg_Dbg( p_mux, "opus stream" );
> +            break;
> +
>          case VLC_CODEC_VORBIS:
>              msg_Dbg( p_mux, "vorbis stream" );
>              break;
> @@ -626,6 +630,7 @@ static block_t *OggCreateHeader( sout_mux_t *p_mux )
>  
>              if( p_stream->i_fourcc == VLC_CODEC_VORBIS ||
>                  p_stream->i_fourcc == VLC_CODEC_SPEEX ||
> +                p_stream->i_fourcc == VLC_CODEC_OPUS ||
>                  p_stream->i_fourcc == VLC_CODEC_THEORA )
>              {
>                  /* First packet in order: vorbis/speex/theora info */
> @@ -713,6 +718,7 @@ static block_t *OggCreateHeader( sout_mux_t *p_mux )
>  
>          if( p_stream->i_fourcc == VLC_CODEC_VORBIS ||
>              p_stream->i_fourcc == VLC_CODEC_SPEEX ||
> +            p_stream->i_fourcc == VLC_CODEC_OPUS ||
>              p_stream->i_fourcc == VLC_CODEC_THEORA )
>          {
>              unsigned pi_size[XIPH_MAX_HEADER_COUNT];
> @@ -977,6 +983,7 @@ static int MuxBlock( sout_mux_t *p_mux, sout_input_t *p_input )
>      if( p_stream->i_fourcc != VLC_CODEC_VORBIS &&
>          p_stream->i_fourcc != VLC_CODEC_FLAC &&
>          p_stream->i_fourcc != VLC_CODEC_SPEEX &&
> +        p_stream->i_fourcc != VLC_CODEC_OPUS &&
>          p_stream->i_fourcc != VLC_CODEC_THEORA &&
>          p_stream->i_fourcc != VLC_CODEC_DIRAC )
>      {
> @@ -994,6 +1001,7 @@ static int MuxBlock( sout_mux_t *p_mux, sout_input_t *p_input )
>      {
>          if( p_stream->i_fourcc == VLC_CODEC_VORBIS ||
>              p_stream->i_fourcc == VLC_CODEC_FLAC ||
> +            p_stream->i_fourcc == VLC_CODEC_OPUS ||
>              p_stream->i_fourcc == VLC_CODEC_SPEEX )
>          {
>              /* number of sample from begining + current packet */
> -- 
> 1.8.1.2
> 
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Regards,

-- 
Denis Charmet - TypX
Le mauvais esprit est un art de vivre



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