2018-10-10 1:15 GMT+02:00, bananaman...@gmail.com <bananaman...@gmail.com>:
> From: bnnm <bananaman...@gmail.com>
>
> Improves trac issue #6722. Fixes truncated WMAPRO/XMA output due to delay
> samples and partially applies bitstream gapless info.
>
> This can be tested with files encoding a small nb_samples (like 400), which
> couldn't output anything due to missing delay at the end.
>
> Applying end_skip and partial delay samples would require some extra
> changes, so files are slightly bigger than what should be.
>
> Signed-off-by: bnnm <bananaman...@gmail.com>
> ---
> libavcodec/wmaprodec.c | 100
> ++++++++++++++++++++++++++++++++++++-------------
> tests/fate/wma.mak | 1 +
> 2 files changed, 74 insertions(+), 27 deletions(-)
>
> diff --git a/libavcodec/wmaprodec.c b/libavcodec/wmaprodec.c
> index 9439bfa771..e18e2e438f 100644
> --- a/libavcodec/wmaprodec.c
> +++ b/libavcodec/wmaprodec.c
> @@ -216,9 +216,9 @@ typedef struct WMAProDecodeCtx {
> GetBitContext gb; ///< bitstream reader
> context
> int buf_bit_size; ///< buffer size in
> bits
> uint8_t drc_gain; ///< gain for the DRC
> tool
> - int8_t skip_frame; ///< skip output step
> int8_t parsed_all_subframes; ///< all subframes
> decoded?
> uint8_t skip_packets; ///< packets to skip to
> find next packet in a stream (XMA1/2)
> + int8_t eof_done; ///< set when EOF
> reached and extra subframe is written (XMA1/2)
>
> /* subframe/block decode state */
> int16_t subframe_len; ///< current subframe
> length
> @@ -379,12 +379,6 @@ static av_cold int decode_init(WMAProDecodeCtx *s,
> AVCodecContext *avctx, int nu
> return AVERROR_PATCHWELCOME;
> }
>
> - /** frame info */
> - if (avctx->codec_id != AV_CODEC_ID_WMAPRO)
> - s->skip_frame = 0;
> - else
> - s->skip_frame = 1; /* skip first frame */
> -
> s->packet_loss = 1;
> s->len_prefix = (s->decode_flags & 0x40);
>
> @@ -1450,21 +1444,38 @@ static int decode_frame(WMAProDecodeCtx *s, AVFrame
> *frame, int *got_frame_ptr)
> ff_dlog(s->avctx, "drc_gain %i\n", s->drc_gain);
> }
>
> - /** no idea what these are for, might be the number of samples
> - that need to be skipped at the beginning or end of a stream */
> + /** read encoder delay/padding (gapless) info */
> if (get_bits1(gb)) {
> - int av_unused skip;
> + int start_skip, end_skip;
> +
>
> - /** usually true for the first frame */
> + /** usually true for the first frame and equal to 1 frame */
> if (get_bits1(gb)) {
> - skip = get_bits(gb, av_log2(s->samples_per_frame * 2));
> - ff_dlog(s->avctx, "start skip: %i\n", skip);
> + start_skip = get_bits(gb, av_log2(s->samples_per_frame * 2));
> + start_skip = FFMIN(start_skip, s->samples_per_frame);
> +
> + /* must add for XMA to respect starting skip_samples */
> + s->avctx->internal->skip_samples += start_skip;
> }
>
> - /** sometimes true for the last frame */
> + /** usually true for the last frame and less than 1 frame */
> if (get_bits1(gb)) {
> - skip = get_bits(gb, av_log2(s->samples_per_frame * 2));
> - ff_dlog(s->avctx, "end skip: %i\n", skip);
> + end_skip = get_bits(gb, av_log2(s->samples_per_frame * 2));
> + end_skip = FFMIN(end_skip, s->samples_per_frame);
> +
> + //TODO fix end_skip (also needs changes in XMA multistream's
> handling)
> + /* for XMA/WMAPRO end_skip may span last frame + final delay
> samples,
> + * so we'd need some counter to (possibly) skip some in this
> frame and
> + * rest after last frame (buf_size 0), so final samples would
> be:
> + * samples_per_frame + delay_samples - start_skip - end_skip
> + * (files with 1 packet are possible so both skips are
> considered).
> + *
> + * WMAPRO 5.1 in XWMA does't do this and audio is padded
> instead,
> + * and min packets is 2 (assumes only 1/2ch need it). */
> +
> + if (s->avctx->codec_id == AV_CODEC_ID_WMAPRO && s->nb_channels
>> 2) {
> + frame->nb_samples = s->samples_per_frame - end_skip;
> + }
> }
>
> }
> @@ -1500,13 +1511,9 @@ static int decode_frame(WMAProDecodeCtx *s, AVFrame
> *frame, int *got_frame_ptr)
> s->samples_per_frame * sizeof(*s->channel[i].out) >> 1);
> }
>
> - if (s->skip_frame) {
> - s->skip_frame = 0;
> - *got_frame_ptr = 0;
> - av_frame_unref(frame);
> - } else {
> - *got_frame_ptr = 1;
> - }
> + /** frame may be partially discarded with gapless info in the bitstream
> */
> + *got_frame_ptr = 1;
> +
>
> if (s->len_prefix) {
> if (len != (get_bits_count(gb) - s->frame_offset) + 2) {
> @@ -1609,7 +1616,35 @@ static int decode_packet(AVCodecContext *avctx,
> WMAProDecodeCtx *s,
>
> *got_frame_ptr = 0;
>
> - if (s->packet_done || s->packet_loss) {
> + if (!buf_size) {
> + AVFrame *frame = data;
> + int i;
> +
> + /** Must output remaining samples after stream end. WMAPRO 5.1
> created
> + * by XWMA encoder don't though; assuming only 1/2ch streams need
> it. */
> + s->packet_done = 0;
> + if (s->eof_done || s->nb_channels > 2)
> + return 0;
> +
> + /** clean output buffer and copy last IMCDT samples */
> + for (i = 0; i < s->nb_channels; i++) {
> + memset(frame->extended_data[i], 0,
> + s->samples_per_frame * sizeof(*s->channel[i].out));
> +
> + memcpy(frame->extended_data[i], s->channel[i].out,
> + s->samples_per_frame * sizeof(*s->channel[i].out) >> 1);
> + }
> +
> + /* TODO: change nb_samples to delay_samples. XMA always uses 128
> + * (with 512 samples per frame) and WMAPRO may use 768 (2048
> s.p.f.).
> + * XMA needs changes in multi-stream handling though. */
> +
> + s->eof_done = 1;
> + s->packet_done = 1;
> + *got_frame_ptr = 1;
> + return 0;
> + }
> + else if (s->packet_done || s->packet_loss) {
> s->packet_done = 0;
>
> /** sanity check for the buffer length */
> @@ -1896,6 +1931,12 @@ static av_cold int xma_decode_init(AVCodecContext
> *avctx)
> start_channels += s->xma[i].nb_channels;
> }
>
> + /** XMA seems to require this to create gapless files (WMAPRO encoder
> + * pads files with silence, while XMA can encode any nb_samples).
> + * This value seems to counter the extra subframe output at EOF
> + * (or perhaps, XMA decoder should output 64 samples earlier?) */
> + avctx->internal->skip_samples = 128/2;
> +
> return ret;
> }
>
> @@ -1922,6 +1963,7 @@ static void flush(WMAProDecodeCtx *s)
> sizeof(*s->channel[i].out));
> s->packet_loss = 1;
> s->skip_packets = 0;
> + s->eof_done = 0;
> }
>
>
> @@ -1934,6 +1976,8 @@ static void wmapro_flush(AVCodecContext *avctx)
> WMAProDecodeCtx *s = avctx->priv_data;
>
> flush(s);
> +
> + avctx->internal->skip_samples = 0;
> }
>
> static void xma_flush(AVCodecContext *avctx)
> @@ -1946,6 +1990,8 @@ static void xma_flush(AVCodecContext *avctx)
>
> memset(s->offset, 0, sizeof(s->offset));
> s->current_stream = 0;
> +
> + avctx->internal->skip_samples = 128/2;
> }
>
>
> @@ -1961,7 +2007,7 @@ AVCodec ff_wmapro_decoder = {
> .init = wmapro_decode_init,
> .close = wmapro_decode_end,
> .decode = wmapro_decode_packet,
> - .capabilities = AV_CODEC_CAP_SUBFRAMES | AV_CODEC_CAP_DR1,
> + .capabilities = AV_CODEC_CAP_SUBFRAMES | AV_CODEC_CAP_DR1 |
> AV_CODEC_CAP_DELAY,
> .flush = wmapro_flush,
> .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
> AV_SAMPLE_FMT_NONE },
> @@ -1976,7 +2022,7 @@ AVCodec ff_xma1_decoder = {
> .init = xma_decode_init,
> .close = xma_decode_end,
> .decode = xma_decode_packet,
> - .capabilities = AV_CODEC_CAP_SUBFRAMES | AV_CODEC_CAP_DR1,
> + .capabilities = AV_CODEC_CAP_SUBFRAMES | AV_CODEC_CAP_DR1 |
> AV_CODEC_CAP_DELAY,
> .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
> AV_SAMPLE_FMT_NONE },
> };
> @@ -1991,7 +2037,7 @@ AVCodec ff_xma2_decoder = {
> .close = xma_decode_end,
> .decode = xma_decode_packet,
> .flush = xma_flush,
> - .capabilities = AV_CODEC_CAP_SUBFRAMES | AV_CODEC_CAP_DR1,
> + .capabilities = AV_CODEC_CAP_SUBFRAMES | AV_CODEC_CAP_DR1 |
> AV_CODEC_CAP_DELAY,
> .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
> AV_SAMPLE_FMT_NONE },
> };
> diff --git a/tests/fate/wma.mak b/tests/fate/wma.mak
> index 12a8fa989a..9c7ce6fd7d 100644
> --- a/tests/fate/wma.mak
> +++ b/tests/fate/wma.mak
> @@ -11,6 +11,7 @@ fate-wmapro-5.1: SIZE_TOLERANCE = 24576
> FATE_WMAPRO-$(call DEMDEC, MOV, WMAPRO) += fate-wmapro-ism
> fate-wmapro-ism: CMD = pcm -i $(TARGET_SAMPLES)/isom/vc1-wmapro.ism -vn
> fate-wmapro-ism: REF = $(SAMPLES)/isom/vc1-wmapro.pcm
> +fate-wmapro-ism: SIZE_TOLERANCE = 12976
Can you confirm that if you break the decoder intentionally, the test
(still) fails?
Thank you, Carl Eugen
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