From 86c092a0edcb3133e7e62fa30d19e80da8e7e849 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sat, 26 Aug 2023 14:27:49 +0200 Subject: [PATCH] avcodec/apedec: Implement interim mode detection Fixes: NoLegacy.ape Found-by: Matt Ashland Signed-off-by: Michael Niedermayer --- libavcodec/apedec.c | 108 ++++++++++++++++++++++++++++++++++---------- 1 file changed, 85 insertions(+), 23 deletions(-) diff --git a/libavcodec/apedec.c b/libavcodec/apedec.c index 8bd625ca05..62cb397490 100644 --- a/libavcodec/apedec.c +++ b/libavcodec/apedec.c @@ -171,6 +171,9 @@ typedef struct APEContext { int32_t *decoded_buffer; int decoded_size; int32_t *decoded[MAX_CHANNELS]; ///< decoded data for each channel + int32_t *interim_buffer; + int interim_size; + int32_t *interim[MAX_CHANNELS]; ///< decoded data for each channel int blocks_per_loop; ///< maximum number of samples to decode for each call int16_t* filterbuf[APE_FILTER_LEVELS]; ///< filter memory @@ -187,6 +190,7 @@ typedef struct APEContext { const uint8_t *ptr; ///< current position in frame data int error; + int interim_mode; void (*entropy_decode_mono)(struct APEContext *ctx, int blockstodecode); void (*entropy_decode_stereo)(struct APEContext *ctx, int blockstodecode); @@ -223,6 +227,7 @@ static av_cold int ape_decode_close(AVCodecContext *avctx) av_freep(&s->filterbuf[i]); av_freep(&s->decoded_buffer); + av_freep(&s->interim_buffer); av_freep(&s->data); s->decoded_size = s->data_size = 0; @@ -248,12 +253,15 @@ static av_cold int ape_decode_init(AVCodecContext *avctx) switch (s->bps) { case 8: avctx->sample_fmt = AV_SAMPLE_FMT_U8P; + s->interim_mode = 0; break; case 16: avctx->sample_fmt = AV_SAMPLE_FMT_S16P; + s->interim_mode = 0; break; case 24: avctx->sample_fmt = AV_SAMPLE_FMT_S32P; + s->interim_mode = -1; break; default: avpriv_request_sample(avctx, @@ -1181,7 +1189,7 @@ static av_always_inline int predictor_update_filter(APEPredictor64 *p, const int decoded, const int filter, const int delayA, const int delayB, const int adaptA, const int adaptB, - int compression_level) + int interim_mode) { int64_t predictionA, predictionB; int32_t sign; @@ -1209,7 +1217,7 @@ static av_always_inline int predictor_update_filter(APEPredictor64 *p, p->buf[delayB - 3] * p->coeffsB[filter][3] + p->buf[delayB - 4] * p->coeffsB[filter][4]; - if (compression_level < COMPRESSION_LEVEL_INSANE) { + if (interim_mode < 1) { predictionA = (int32_t)predictionA; predictionB = (int32_t)predictionB; p->lastA[filter] = decoded + ((int32_t)(predictionA + (predictionB >> 1)) >> 10); @@ -1234,32 +1242,73 @@ static av_always_inline int predictor_update_filter(APEPredictor64 *p, static void predictor_decode_stereo_3950(APEContext *ctx, int count) { - APEPredictor64 *p = &ctx->predictor64; - int32_t *decoded0 = ctx->decoded[0]; - int32_t *decoded1 = ctx->decoded[1]; + APEPredictor64 *p_default = &ctx->predictor64; + APEPredictor64 p_interim; + int lcount = count; + int num_passes = 1; ape_apply_filters(ctx, ctx->decoded[0], ctx->decoded[1], count); + if (ctx->interim_mode == -1) { + p_interim = *p_default; + num_passes ++; + memcpy(ctx->interim[0], ctx->decoded[0], sizeof(*ctx->interim[0])*count); + memcpy(ctx->interim[1], ctx->decoded[1], sizeof(*ctx->interim[1])*count); + } - while (count--) { - /* Predictor Y */ - *decoded0 = predictor_update_filter(p, *decoded0, 0, YDELAYA, YDELAYB, - YADAPTCOEFFSA, YADAPTCOEFFSB, - ctx->compression_level); - decoded0++; - *decoded1 = predictor_update_filter(p, *decoded1, 1, XDELAYA, XDELAYB, - XADAPTCOEFFSA, XADAPTCOEFFSB, - ctx->compression_level); - decoded1++; + for (int pass = 0; pass < num_passes; pass++) { + int32_t *decoded0, *decoded1; + int interim_mode = ctx->interim_mode > 0 || pass; + APEPredictor64 *p; - /* Combined */ - p->buf++; - - /* Have we filled the history buffer? */ - if (p->buf == p->historybuffer + HISTORY_SIZE) { - memmove(p->historybuffer, p->buf, - PREDICTOR_SIZE * sizeof(*p->historybuffer)); - p->buf = p->historybuffer; + if (pass) { + p = &p_interim; + decoded0 = ctx->interim[0]; + decoded1 = ctx->interim[1]; + } else { + p = p_default; + decoded0 = ctx->decoded[0]; + decoded1 = ctx->decoded[1]; } + p->buf = p->historybuffer; + + count = lcount; + while (count--) { + /* Predictor Y */ + int32_t a0 = predictor_update_filter(p, *decoded0, 0, YDELAYA, YDELAYB, + YADAPTCOEFFSA, YADAPTCOEFFSB, + interim_mode); + int32_t a1 = predictor_update_filter(p, *decoded1, 1, XDELAYA, XDELAYB, + XADAPTCOEFFSA, XADAPTCOEFFSB, + interim_mode); + *decoded0++ = a0; + *decoded1++ = a1; + if (num_passes > 1) { + int32_t left = a1 - (unsigned)(a0 / 2); + int32_t right = left + a0; + + if (FFMAX(FFABS(left), FFABS(right)) > (1<<23)) { + ctx->interim_mode = !interim_mode; + av_log(ctx->avctx, AV_LOG_VERBOSE, "Interim mode: %d\n", ctx->interim_mode); + break; + } + } + + /* Combined */ + p->buf++; + + /* Have we filled the history buffer? */ + if (p->buf == p->historybuffer + HISTORY_SIZE) { + memmove(p->historybuffer, p->buf, + PREDICTOR_SIZE * sizeof(*p->historybuffer)); + p->buf = p->historybuffer; + } + } + } + if (num_passes > 1 && ctx->interim_mode > 0) { + memcpy(ctx->decoded[0], ctx->interim[0], sizeof(*ctx->interim[0])*lcount); + memcpy(ctx->decoded[1], ctx->interim[1], sizeof(*ctx->interim[1])*lcount); + *p_default = p_interim; + p_default->buf = p_default->historybuffer; } } @@ -1590,6 +1639,19 @@ static int ape_decode_frame(AVCodecContext *avctx, AVFrame *frame, s->decoded[0] = s->decoded_buffer; s->decoded[1] = s->decoded_buffer + FFALIGN(blockstodecode, 8); + if (s->interim_mode < 0) { + av_fast_malloc(&s->interim_buffer, &s->interim_size, decoded_buffer_size); + if (!s->interim_buffer) + return AVERROR(ENOMEM); + memset(s->interim_buffer, 0, decoded_buffer_size); + s->interim[0] = s->interim_buffer; + s->interim[1] = s->interim_buffer + FFALIGN(blockstodecode, 8); + } else { + av_freep(&s->interim_buffer); + s->interim_size = 0; + memset(s->interim, 0, sizeof(s->interim)); + } + s->error=0; if ((s->channels == 1) || (s->frameflags & APE_FRAMECODE_PSEUDO_STEREO))