On Sun, Sep 10, 2023 at 1:59 PM Andreas Rheinhardt < andreas.rheinha...@outlook.com> wrote:
> Paul B Mahol: > > On Wed, Sep 6, 2023 at 1:30 PM Andreas Rheinhardt < > > andreas.rheinha...@outlook.com> wrote: > > > >> Paul B Mahol: > >>> On Wed, Sep 6, 2023 at 11:26 AM Andreas Rheinhardt < > >>> andreas.rheinha...@outlook.com> wrote: > >>> > >>>> Paul B Mahol: > >>>>> > >>>>> + chunk_type = avio_rb32(pb); > >>>>> + chunk_size = avio_rb32(pb); > >>>> > >>>> You are not checking whether the chunk here exceeds its containing > >> chunk. > >>>> > >>>>> > >>>>> + av_fast_malloc(&usm->header, &usm->header_size, > >>>>> + chunk_size + AV_INPUT_BUFFER_PADDING_SIZE); > >>>>> + if (!usm->header) > >>>>> + return AVERROR(ENOMEM); > >>>> > >>>> The bytestream2 API does not rely on the buffer being padded at all. > >>>> > >>>>> > >>>>> + bytestream2_skip(&sgb, string_offset); > >>>> > >>>> This is unnecessary, because you seek with an absolute offset lateron > >>>> anyway before using sgb. > >>>> > >>>>> > >>>>> + bytestream2_seek(&sgb, string_offset + offset, SEEK_SET); > >>>>> + while (bytestream2_get_bytes_left(&sgb) > 0) { > >>>>> + key[n] = bytestream2_get_byte(&sgb); > >>>>> + if (!key[n]) > >>>>> + break; > >>>>> + if (n >= sizeof(key) - 1) > >>>>> + break; > >>>>> + n++; > >>>>> + } > >>>>> + key[n] = '\0'; > >>>> > >>>> IMO this would be easier with strnlen(), avoiding sgb altogether. > >>>> You would of course need to explicitly check that you are not > >>>> overreading, but that is good practice anyway. > >>>> > >>>>> > >>>>> + chunk_start = avio_tell(pb); > >>>>> + avio_skip(pb, 1); > >>>>> + payload_offset = avio_r8(pb); > >>>>> + padding_size = avio_rb16(pb); > >>>>> + stream_index = avio_r8(pb); > >>>>> + avio_skip(pb, 2); > >>>>> + payload_type = avio_r8(pb); > >>>>> + frame_time = avio_rb32(pb); > >>>>> + frame_rate = avio_rb32(pb); > >>>>> + avio_skip(pb, 8); > >>>> > >>>> payload_offset and frame_time are set-but-unused; this might lead to > >>>> compiler warnings. > >>>> > >>>>> + if (usm->ch[is_audio][stream_index].used == 1) { > >>>>> + uint32_t pkt_size = chunk_size - (avio_tell(pb) - > >>>> chunk_start); > >>>>> + > >>>> > >>>> This is unnecessary: Unless we already had a read error, pkt_size is > >>>> chunk_size - (1 + 1 + 2 + 1 + 2 + 1 + 4 + 4 + 8). > >>>> > >>>> (Notice that in case padding_size is > 0, it will be part of the > packet > >>>> with the current code; not sure if that is an issue.) > >>>> > >>>>> > >>>>> + > >>>>> + avio_skip(pb, padding_size); > >>>>> + avio_skip(pb, chunk_size - (avio_tell(pb) - chunk_start)); > >>>>> + > >>>> > >>>> Simpler to just use avio_seek(pb, chunk_start + chunk_size, SEEK_SET); > >>>> > >>> > >>> But input might not be seekable. > >>> > >> > >> And? You know that avio_skip(pb, offset) is just avio_seek(pb, offset, > >> SEEK_CUR)? > >> > > > > And? Do you know that SEEK_SET is different from SEEK_CUR with positive > > argument. > > > > You are using SEEK_CUR with -avio_tell(pb), which effectively makes it > an absolute seek. > Nope, I skip data only, not seeking backward ever. > > - Andreas > > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe". > _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".