[FFmpeg-devel] [PATCH 5/7] lavf/flacenc: support writing attached pictures

James Almer jamrial at gmail.com
Fri May 12 20:41:33 EEST 2017


On 5/8/2017 1:36 AM, Rodger Combs wrote:
> ---
>  libavformat/flacenc.c | 271 +++++++++++++++++++++++++++++++++++++++++++-------
>  1 file changed, 236 insertions(+), 35 deletions(-)
> 
> diff --git a/libavformat/flacenc.c b/libavformat/flacenc.c
> index b894f9e..9bb4947 100644
> --- a/libavformat/flacenc.c
> +++ b/libavformat/flacenc.c
> @@ -21,10 +21,13 @@
>  
>  #include "libavutil/channel_layout.h"
>  #include "libavutil/opt.h"
> +#include "libavutil/pixdesc.h"
>  #include "libavcodec/flac.h"
>  #include "avformat.h"
>  #include "avio_internal.h"
>  #include "flacenc.h"
> +#include "id3v2.h"
> +#include "internal.h"
>  #include "vorbiscomment.h"
>  #include "libavcodec/bytestream.h"
>  
> @@ -33,8 +36,16 @@ typedef struct FlacMuxerContext {
>      const AVClass *class;
>      int write_header;
>  
> +    int audio_stream_idx;
> +    AVPacket *pics;
> +    int nb_pics, waiting_pics;
> +    /* audio packets are queued here until we get all the attached pictures */
> +    AVPacketList *queue, *queue_end;
> +
>      /* updated streaminfo sent by the encoder at the end */
>      uint8_t *streaminfo;
> +
> +    unsigned attached_types;
>  } FlacMuxerContext;
>  
>  static int flac_write_block_padding(AVIOContext *pb, unsigned int n_padding_bytes,
> @@ -74,31 +85,149 @@ static int flac_write_block_comment(AVIOContext *pb, AVDictionary **m,
>      return 0;
>  }
>  
> -static int flac_write_header(struct AVFormatContext *s)
> +static int flac_write_picture(struct AVFormatContext *s, AVPacket *pkt)
>  {
> -    int ret;
> -    int padding = s->metadata_header_padding;
> -    AVCodecParameters *par = s->streams[0]->codecpar;
> -    FlacMuxerContext *c   = s->priv_data;
> -
> -    if (!c->write_header)
> +    FlacMuxerContext *c = s->priv_data;
> +    AVIOContext *pb = s->pb;
> +    const AVPixFmtDescriptor *pixdesc;
> +    const CodecMime *mime = ff_id3v2_mime_tags;
> +    AVDictionaryEntry *e;
> +    const char *mimetype = NULL, *desc = "";
> +    const AVStream *st = s->streams[pkt->stream_index];
> +    int i, mimelen, desclen, type = 0;
> +
> +    if (!pkt->data)
>          return 0;
>  
> -    if (s->nb_streams > 1) {
> -        av_log(s, AV_LOG_ERROR, "only one stream is supported\n");
> +    while (mime->id != AV_CODEC_ID_NONE) {
> +        if (mime->id == st->codecpar->codec_id) {
> +            mimetype = mime->str;
> +            break;
> +        }
> +        mime++;
> +    }
> +    if (!mimetype) {
> +        av_log(s, AV_LOG_ERROR, "No mimetype is known for stream %d, cannot "
> +               "write an attached picture.\n", st->index);
>          return AVERROR(EINVAL);
>      }
> -    if (par->codec_id != AV_CODEC_ID_FLAC) {
> -        av_log(s, AV_LOG_ERROR, "unsupported codec\n");
> +    mimelen = strlen(mimetype);
> +
> +    /* get the picture type */
> +    e = av_dict_get(st->metadata, "comment", NULL, 0);
> +    for (i = 0; e && i < FF_ARRAY_ELEMS(ff_id3v2_picture_types); i++) {
> +        if (!av_strcasecmp(e->value, ff_id3v2_picture_types[i])) {
> +            type = i;
> +            break;
> +        }
> +    }
> +
> +    if (c->attached_types & (1 << type)) {
> +        av_log(s, AV_LOG_ERROR, "Duplicate attachment for type '%s'\n", ff_id3v2_picture_types[type]);
>          return AVERROR(EINVAL);
>      }
>  
> +    c->attached_types |= (1 << type);
> +
> +    /* get the description */
> +    if ((e = av_dict_get(st->metadata, "title", NULL, 0)))
> +        desc = e->value;
> +    desclen = strlen(desc);
> +
> +    avio_w8(pb, 0x06);
> +    avio_wb24(pb, 4 + 4 + mimelen + 4 + desclen + 4 + 4 + 4 + 4 + 4 + pkt->size);
> +
> +    avio_wb32(pb, type);
> +
> +    avio_wb32(pb, mimelen);
> +    avio_write(pb, mimetype, mimelen);
> +
> +    avio_wb32(pb, desclen);
> +    avio_write(pb, desc, desclen);
> +
> +    avio_wb32(pb, st->codecpar->width);
> +    avio_wb32(pb, st->codecpar->height);
> +    if ((pixdesc = av_pix_fmt_desc_get(st->codecpar->format)))
> +        avio_wb32(pb, av_get_bits_per_pixel(pixdesc));
> +    else
> +        avio_wb32(pb, 0);
> +    avio_wb32(pb, 0);
> +
> +    avio_wb32(pb, pkt->size);
> +    avio_write(pb, pkt->data, pkt->size);
> +    return 0;
> +}
> +
> +static int flac_finish_header(struct AVFormatContext *s)
> +{
> +    FlacMuxerContext *c = s->priv_data;
> +    int i, ret, padding = s->metadata_header_padding;
>      if (padding < 0)
>          padding = 8192;
>      /* The FLAC specification states that 24 bits are used to represent the
>       * size of a metadata block so we must clip this value to 2^24-1. */
>      padding = av_clip_uintp2(padding, 24);
>  
> +    for (i = 0; i < c->nb_pics; i++) {
> +        ret = flac_write_picture(s, &c->pics[i]);
> +        if (ret)
> +            return ret;
> +    }
> +
> +    ret = flac_write_block_comment(s->pb, &s->metadata, !padding,
> +                                   s->flags & AVFMT_FLAG_BITEXACT);
> +    if (ret)
> +        return ret;
> +
> +    /* The command line flac encoder defaults to placing a seekpoint
> +     * every 10s.  So one might add padding to allow that later
> +     * but there seems to be no simple way to get the duration here.
> +     * So just add the amount requested by the user. */
> +    if (padding)
> +        flac_write_block_padding(s->pb, padding, 1);
> +
> +    return 0;
> +}
> +
> +static int flac_write_header(struct AVFormatContext *s)
> +{
> +    int ret, i;
> +    AVCodecParameters *par;
> +    FlacMuxerContext *c = s->priv_data;
> +
> +    c->audio_stream_idx = -1;
> +    for (i = 0; i < s->nb_streams; i++) {
> +        AVStream *st = s->streams[i];
> +        if (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO) {
> +            if (c->audio_stream_idx >= 0 || st->codecpar->codec_id != AV_CODEC_ID_FLAC) {
> +                av_log(s, AV_LOG_ERROR, "Invalid audio stream. Exactly one FLAC "
> +                       "audio stream is required.\n");
> +                return AVERROR(EINVAL);
> +            }
> +            par = s->streams[i]->codecpar;
> +            c->audio_stream_idx = i;
> +        } else if (st->codecpar->codec_type != AVMEDIA_TYPE_VIDEO) {
> +            av_log(s, AV_LOG_ERROR, "Only audio streams and pictures are allowed in FLAC.\n");
> +            return AVERROR(EINVAL);
> +        } else if (st->codecpar->codec_id == AV_CODEC_ID_GIF) {
> +            av_log(s, AV_LOG_ERROR, "GIF image support is not implemented.\n");
> +            return AVERROR_PATCHWELCOME;
> +        } else if (!c->write_header) {
> +            av_log(s, AV_LOG_ERROR, "Can't write attached pictures without a header.\n");
> +            return AVERROR(EINVAL);
> +        }
> +    }
> +    if (c->audio_stream_idx < 0) {
> +        av_log(s, AV_LOG_ERROR, "No audio stream present.\n");
> +        return AVERROR(EINVAL);
> +    }
> +    c->waiting_pics = c->nb_pics = s->nb_streams - 1;
> +    if (c->nb_pics && !(c->pics = av_calloc(c->nb_pics, sizeof(AVPacket))))

You never free c->pics on exit, be it success or failure.

> +        return AVERROR(ENOMEM);
> +
> +    if (!c->write_header)
> +        return 0;
> +
>      ret = ff_flac_write_header(s->pb, par->extradata,
>                                 par->extradata_size, 0);
>      if (ret)
> @@ -121,18 +250,51 @@ static int flac_write_header(struct AVFormatContext *s)
>          }
>      }
>  
> -    ret = flac_write_block_comment(s->pb, &s->metadata, !padding,
> -                                   s->flags & AVFMT_FLAG_BITEXACT);
> -    if (ret)
> -        return ret;
> +    if (!c->waiting_pics)
> +        ret = flac_finish_header(s);
>  
> -    /* The command line flac encoder defaults to placing a seekpoint
> -     * every 10s.  So one might add padding to allow that later
> -     * but there seems to be no simple way to get the duration here.
> -     * So just add the amount requested by the user. */
> -    if (padding)
> -        flac_write_block_padding(s->pb, padding, 1);
> +    return ret;
> +}
>  
> +static int flac_write_audio_packet(struct AVFormatContext *s, AVPacket *pkt)
> +{
> +    FlacMuxerContext *c = s->priv_data;
> +    uint8_t *streaminfo;
> +    int streaminfo_size;
> +
> +    /* check for updated streaminfo */
> +    streaminfo = av_packet_get_side_data(pkt, AV_PKT_DATA_NEW_EXTRADATA,
> +                                         &streaminfo_size);
> +    if (streaminfo && streaminfo_size == FLAC_STREAMINFO_SIZE) {
> +        av_freep(&c->streaminfo);
> +
> +        c->streaminfo = av_malloc(FLAC_STREAMINFO_SIZE);
> +        if (!c->streaminfo)
> +            return AVERROR(ENOMEM);
> +        memcpy(c->streaminfo, streaminfo, FLAC_STREAMINFO_SIZE);
> +    }
> +
> +    if (pkt->size)
> +        avio_write(s->pb, pkt->data, pkt->size);
> +    return 0;
> +}
> +
> +static int flac_queue_flush(AVFormatContext *s)
> +{
> +    FlacMuxerContext *c = s->priv_data;
> +    AVPacketList *pktl;
> +    int ret = 0, write = 1;
> +
> +    flac_finish_header(s);
> +
> +    while ((pktl = c->queue)) {
> +        if (write && (ret = flac_write_audio_packet(s, &pktl->pkt)) < 0)
> +            write = 0;
> +        av_packet_unref(&pktl->pkt);
> +        c->queue = pktl->next;
> +        av_freep(&pktl);
> +    }
> +    c->queue_end = NULL;
>      return ret;
>  }
>  
> @@ -144,6 +306,12 @@ static int flac_write_trailer(struct AVFormatContext *s)
>      uint8_t *streaminfo = c->streaminfo ? c->streaminfo :
>                                            s->streams[0]->codecpar->extradata;
>  
> +    if (c->waiting_pics) {
> +        av_log(s, AV_LOG_WARNING, "No packets were sent for some of the "
> +               "attached pictures.\n");
> +        flac_queue_flush(s);
> +    }
> +
>      if (!c->write_header || !streaminfo)
>          return 0;
>  
> @@ -166,23 +334,56 @@ static int flac_write_trailer(struct AVFormatContext *s)
>  static int flac_write_packet(struct AVFormatContext *s, AVPacket *pkt)
>  {
>      FlacMuxerContext *c = s->priv_data;
> -    uint8_t *streaminfo;
> -    int streaminfo_size;
> +    if (pkt->stream_index == c->audio_stream_idx) {
> +        if (c->waiting_pics) {
> +            /* buffer audio packets until we get all the pictures */
> +            AVPacketList *pktl = av_mallocz(sizeof(*pktl));
> +            int ret;
> +            if (!pktl) {
> +oom:
> +                av_log(s, AV_LOG_ERROR, "Out of memory in packet queue; skipping attached pictures\n");
> +                c->waiting_pics = 0;
> +                return flac_write_audio_packet(s, pkt);

Shouldn't this call flac_queue_flush() instead?

> +            }
> +
> +            ret = av_copy_packet(&pktl->pkt, pkt);
> +            if (ret < 0) {
> +                av_freep(&pktl);
> +                goto oom;
> +            }
> +
> +            if (c->queue_end)
> +                c->queue_end->next = pktl;
> +            else
> +                c->queue = pktl;
> +            c->queue_end = pktl;
> +        } else {
> +            return flac_write_audio_packet(s, pkt);
> +        }
> +    } else {
> +        int ret, index = pkt->stream_index;
>  
> -    /* check for updated streaminfo */
> -    streaminfo = av_packet_get_side_data(pkt, AV_PKT_DATA_NEW_EXTRADATA,
> -                                         &streaminfo_size);
> -    if (streaminfo && streaminfo_size == FLAC_STREAMINFO_SIZE) {
> -        av_freep(&c->streaminfo);
> +        /* warn only once for each stream */
> +        if (s->streams[pkt->stream_index]->nb_frames == 1) {
> +            av_log(s, AV_LOG_WARNING, "Got more than one picture in stream %d,"
> +                   " ignoring.\n", pkt->stream_index);
> +        }
> +        if (!c->waiting_pics || s->streams[pkt->stream_index]->nb_frames >= 1)
> +            return 0;
>  
> -        c->streaminfo = av_malloc(FLAC_STREAMINFO_SIZE);
> -        if (!c->streaminfo)
> -            return AVERROR(ENOMEM);
> -        memcpy(c->streaminfo, streaminfo, FLAC_STREAMINFO_SIZE);
> +        if (index > c->audio_stream_idx)
> +            index--;
> +
> +        if ((ret = av_copy_packet(&c->pics[index], pkt)) < 0)
> +            return ret;
> +        c->waiting_pics--;
> +
> +        /* flush the buffered audio packets */
> +        if (!c->waiting_pics &&
> +            (ret = flac_queue_flush(s)) < 0)
> +            return ret;
>      }
>  
> -    if (pkt->size)
> -        avio_write(s->pb, pkt->data, pkt->size);
>      return 0;
>  }
>  
> @@ -205,7 +406,7 @@ AVOutputFormat ff_flac_muxer = {
>      .mime_type         = "audio/x-flac",
>      .extensions        = "flac",
>      .audio_codec       = AV_CODEC_ID_FLAC,
> -    .video_codec       = AV_CODEC_ID_NONE,
> +    .video_codec       = AV_CODEC_ID_PNG,
>      .write_header      = flac_write_header,
>      .write_packet      = flac_write_packet,
>      .write_trailer     = flac_write_trailer,
> 



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