[FFmpeg-devel] [PATCH v8 4/5] ogg/vorbis: implement header packet skip in chained ogg bitstreams.
Romain Beauxis
romain.beauxis at gmail.com
Sun Jun 1 19:21:59 EEST 2025
Le sam. 31 mai 2025 à 15:08, Andreas Rheinhardt
<andreas.rheinhardt at outlook.com> a écrit :
>
> Romain Beauxis:
> > Le ven. 30 mai 2025 à 19:44, Andreas Rheinhardt
> > <andreas.rheinhardt at outlook.com> a écrit :
> >>
> >> Romain Beauxis:
> >>> ---
> >>> libavcodec/vorbis_parser.h | 11 ++++
> >>> libavcodec/vorbisdec.c | 75 +++++++++++++---------
> >>> libavformat/oggparsevorbis.c | 67 ++++++++++++++++++-
> >>> tests/ref/fate/ogg-vorbis-chained-meta.txt | 3 -
> >>> tests/ref/fate/trac-2739.txt | 4 +-
> >>> 5 files changed, 121 insertions(+), 39 deletions(-)
> >>>
> >>> diff --git a/libavcodec/vorbis_parser.h b/libavcodec/vorbis_parser.h
> >>> index 789932ac49..b176fe536c 100644
> >>> --- a/libavcodec/vorbis_parser.h
> >>> +++ b/libavcodec/vorbis_parser.h
> >>> @@ -30,6 +30,17 @@
> >>>
> >>> typedef struct AVVorbisParseContext AVVorbisParseContext;
> >>>
> >>> +/**
> >>> + * Used by the vorbis parser to pass new chained stream headers
> >>> + * as extradata.
> >>> + */
> >>> +typedef struct vorbis_new_extradata {
> >>> + uint8_t *header;
> >>> + size_t header_size;
> >>> + uint8_t *setup;
> >>> + size_t setup_size;
> >>> +} vorbis_new_extradata;
> >>> +
> >>> /**
> >>> * Allocate and initialize the Vorbis parser using headers in the extradata.
> >>> */
> >>> diff --git a/libavcodec/vorbisdec.c b/libavcodec/vorbisdec.c
> >>> index adbd726183..a4b159ba9b 100644
> >>> --- a/libavcodec/vorbisdec.c
> >>> +++ b/libavcodec/vorbisdec.c
> >>> @@ -43,6 +43,7 @@
> >>> #include "vorbis.h"
> >>> #include "vorbisdsp.h"
> >>> #include "vorbis_data.h"
> >>> +#include "vorbis_parser.h"
> >>> #include "xiph.h"
> >>>
> >>> #define V_NB_BITS 8
> >>> @@ -1778,47 +1779,59 @@ static int vorbis_decode_frame(AVCodecContext *avctx, AVFrame *frame,
> >>> GetBitContext *gb = &vc->gb;
> >>> float *channel_ptrs[255];
> >>> int i, len, ret;
> >>> + size_t new_extradata_size;
> >>> + vorbis_new_extradata *new_extradata;
> >>> + const uint8_t *header;
> >>> + const uint8_t *setup;
> >>>
> >>> ff_dlog(NULL, "packet length %d \n", buf_size);
> >>>
> >>> - if (*buf == 1 && buf_size > 7) {
> >>> - if ((ret = init_get_bits8(gb, buf + 1, buf_size - 1)) < 0)
> >>> - return ret;
> >>> + new_extradata = (vorbis_new_extradata *)av_packet_get_side_data(
> >>> + avpkt, AV_PKT_DATA_NEW_EXTRADATA, &new_extradata_size);
> >>>
> >>> - vorbis_free(vc);
> >>> - if ((ret = vorbis_parse_id_hdr(vc))) {
> >>> - av_log(avctx, AV_LOG_ERROR, "Id header corrupt.\n");
> >>> - vorbis_free(vc);
> >>> - return ret;
> >>> - }
> >>> + if (new_extradata) {
> >>> + header = new_extradata->header;
> >>> + setup = new_extradata->setup;
> >>>
> >>> - av_channel_layout_uninit(&avctx->ch_layout);
> >>> - if (vc->audio_channels > 8) {
> >>> - avctx->ch_layout.order = AV_CHANNEL_ORDER_UNSPEC;
> >>> - avctx->ch_layout.nb_channels = vc->audio_channels;
> >>> - } else {
> >>> - av_channel_layout_copy(&avctx->ch_layout, &ff_vorbis_ch_layouts[vc->audio_channels - 1]);
> >>> - }
> >>> + if (new_extradata->header_size > 7 && *header == 1) {
> >>> + if ((ret = init_get_bits8(
> >>> + gb, header + 1,
> >>> + new_extradata->header_size - 1)) < 0)
> >>> + return ret;
> >>>
> >>> - avctx->sample_rate = vc->audio_samplerate;
> >>> - return buf_size;
> >>> - }
> >>> + vorbis_free(vc);
> >>> + if ((ret = vorbis_parse_id_hdr(vc))) {
> >>> + av_log(avctx, AV_LOG_ERROR, "Id header corrupt.\n");
> >>> + vorbis_free(vc);
> >>> + return ret;
> >>> + }
> >>>
> >>> - if (*buf == 3 && buf_size > 7) {
> >>> - av_log(avctx, AV_LOG_DEBUG, "Ignoring comment header\n");
> >>> - return buf_size;
> >>> - }
> >>> + av_channel_layout_uninit(&avctx->ch_layout);
> >>> + if (vc->audio_channels > 8) {
> >>> + avctx->ch_layout.order = AV_CHANNEL_ORDER_UNSPEC;
> >>> + avctx->ch_layout.nb_channels = vc->audio_channels;
> >>> + } else {
> >>> + av_channel_layout_copy(
> >>> + &avctx->ch_layout,
> >>> + &ff_vorbis_ch_layouts[vc->audio_channels - 1]);
> >>> + }
> >>>
> >>> - if (*buf == 5 && buf_size > 7 && vc->channel_residues && !vc->modes) {
> >>> - if ((ret = init_get_bits8(gb, buf + 1, buf_size - 1)) < 0)
> >>> - return ret;
> >>> + avctx->sample_rate = vc->audio_samplerate;
> >>> + }
> >>>
> >>> - if ((ret = vorbis_parse_setup_hdr(vc))) {
> >>> - av_log(avctx, AV_LOG_ERROR, "Setup header corrupt.\n");
> >>> - vorbis_free(vc);
> >>> - return ret;
> >>> + if (new_extradata->setup_size > 7 && *setup == 5 &&
> >>> + vc->channel_residues && !vc->modes) {
> >>> + if ((ret = init_get_bits8(
> >>> + gb, setup + 1,
> >>> + new_extradata->setup_size - 1)) < 0)
> >>> + return ret;
> >>> +
> >>> + if ((ret = vorbis_parse_setup_hdr(vc))) {
> >>> + av_log(avctx, AV_LOG_ERROR, "Setup header corrupt.\n");
> >>> + vorbis_free(vc);
> >>> + return ret;
> >>> + }
> >>> }
> >>> - return buf_size;
> >>> }
> >>>
> >>> if (!vc->channel_residues || !vc->modes) {
> >>> diff --git a/libavformat/oggparsevorbis.c b/libavformat/oggparsevorbis.c
> >>> index 62cc2da6de..f8e66e8127 100644
> >>> --- a/libavformat/oggparsevorbis.c
> >>> +++ b/libavformat/oggparsevorbis.c
> >>> @@ -255,12 +255,19 @@ static void vorbis_cleanup(AVFormatContext *s, int idx)
> >>> struct ogg *ogg = s->priv_data;
> >>> struct ogg_stream *os = ogg->streams + idx;
> >>> struct oggvorbis_private *priv = os->private;
> >>> + vorbis_new_extradata *new_extradata;
> >>> int i;
> >>> if (os->private) {
> >>> av_vorbis_parse_free(&priv->vp);
> >>> for (i = 0; i < 3; i++)
> >>> av_freep(&priv->packet[i]);
> >>> }
> >>> +
> >>> + if (os->new_extradata) {
> >>> + new_extradata = (vorbis_new_extradata *)os->new_extradata;
> >>> + av_freep(&new_extradata->header);
> >>> + av_freep(&new_extradata->setup);
> >>> + }
> >>> }
> >>>
> >>> static int vorbis_update_metadata(AVFormatContext *s, int idx)
> >>> @@ -433,7 +440,10 @@ static int vorbis_packet(AVFormatContext *s, int idx)
> >>> struct ogg *ogg = s->priv_data;
> >>> struct ogg_stream *os = ogg->streams + idx;
> >>> struct oggvorbis_private *priv = os->private;
> >>> + vorbis_new_extradata *new_extradata;
> >>> int duration, flags = 0;
> >>> + int skip_packet = 0;
> >>> + int ret;
> >>>
> >>> if (!priv->vp)
> >>> return AVERROR_INVALIDDATA;
> >>> @@ -496,10 +506,61 @@ static int vorbis_packet(AVFormatContext *s, int idx)
> >>> if (duration < 0) {
> >>> os->pflags |= AV_PKT_FLAG_CORRUPT;
> >>> return 0;
> >>> - } else if (flags & VORBIS_FLAG_COMMENT) {
> >>> - vorbis_update_metadata(s, idx);
> >>> + }
> >>> +
> >>> + if (flags & VORBIS_FLAG_HEADER) {
> >>> + ret = vorbis_parse_header(s, s->streams[idx], os->buf + os->pstart, os->psize);
> >>> + if (ret < 0)
> >>> + return ret;
> >>> +
> >>> + if (!os->new_extradata) {
> >>> + os->new_extradata = av_mallocz(sizeof(vorbis_new_extradata));
> >>> + if (!os->new_extradata)
> >>> + return AVERROR(ENOMEM);
> >>> + }
> >>> +
> >>> + os->new_extradata_size = sizeof(vorbis_new_extradata);
> >>> + new_extradata = (vorbis_new_extradata *)os->new_extradata;
> >>> +
> >>> + ret = av_reallocp(&new_extradata->header, os->psize);
> >>> + if (ret < 0)
> >>> + return ret;
> >>> +
> >>> + memcpy(new_extradata->header, os->buf + os->pstart, os->psize);
> >>> + new_extradata->header_size = os->psize;
> >>> +
> >>> + skip_packet = 1;
> >>> + }
> >>> +
> >>> + if (flags & VORBIS_FLAG_COMMENT) {
> >>> + ret = vorbis_update_metadata(s, idx);
> >>> + if (ret < 0)
> >>> + return ret;
> >>> +
> >>> flags = 0;
> >>> + skip_packet = 1;
> >>> + }
> >>> +
> >>> + if (flags & VORBIS_FLAG_SETUP) {
> >>> + if (!os->new_extradata) {
> >>> + os->new_extradata = av_mallocz(sizeof(vorbis_new_extradata));
> >>> + if (!os->new_extradata)
> >>> + return AVERROR(ENOMEM);
> >>> + }
> >>> +
> >>> + os->new_extradata_size = sizeof(vorbis_new_extradata);
> >>> + new_extradata = (vorbis_new_extradata *)os->new_extradata;
> >>> +
> >>> + ret = av_reallocp(&new_extradata->setup, os->psize);
> >>> + if (ret < 0)
> >>> + return ret;
> >>> +
> >>> + memcpy(new_extradata->setup, os->buf + os->pstart, os->psize);
> >>> + new_extradata->setup_size = os->psize;
> >>> +
> >>> + skip_packet = 1;
> >>> }
> >>> +
> >>> os->pduration = duration;
> >>> }
> >>>
> >>> @@ -521,7 +582,7 @@ static int vorbis_packet(AVFormatContext *s, int idx)
> >>> priv->final_duration += os->pduration;
> >>> }
> >>>
> >>> - return 0;
> >>> + return skip_packet;
> >>> }
> >>>
> >>> const struct ogg_codec ff_vorbis_codec = {
> >>
> >> There are multiple issues with this patch:
> >
> > Thank you for your feedback.
> >
> >> 1. The side data structures are not padded, leading to
> >> heap-buffer-overflows in the fate-ogg-vorbis-chained-meta test.
> >
> > Do you have a pointer to this issue? Is there a failing test here:
> > https://fate.ffmpeg.org/ ?
> >
>
> I noted it when I ran FATE with (Clang-)ASAN locally. Seems like none of
> the ASAN/valgrind fate boxes tested your commit.
>
> >> 2. The side data structures are not flat and therefore not suitable for
> >> use as AVPacketSideData. (The setup and header arrays are currently
> >> owned by the demuxer, yet an AVPacket is supposed to be valid on its
> >> own. But this side data becomes invalid when the demuxer encounters a
> >> new side data (and reallocates its internal buffers) or when the demuxer
> >> is closed.)
> >
> > I can work on that.
>
> Actually, thinking about this a bit more: New extradata via side data
> should use the same format as ordinary extradata, so there is no need to
> add a new struct and APIchanges for that.
Just sent an updated patch, let me know what you think!
Thanks,
-- Romain
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