From patchwork Fri Oct 2 22:23:41 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicolas Gaullier X-Patchwork-Id: 22707 Return-Path: X-Original-To: patchwork@ffaux-bg.ffmpeg.org Delivered-To: patchwork@ffaux-bg.ffmpeg.org Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org [79.124.17.100]) by ffaux.localdomain (Postfix) with ESMTP id A3B9744BDEC for ; Sat, 3 Oct 2020 01:24:05 +0300 (EEST) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 8CFB968A760; Sat, 3 Oct 2020 01:24:05 +0300 (EEST) X-Original-To: ffmpeg-devel@ffmpeg.org Delivered-To: ffmpeg-devel@ffmpeg.org Received: from srv-infra-1.infra.inf.glb.tvvideoms.com (unknown [213.205.126.156]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 93273689F05 for ; Sat, 3 Oct 2020 01:23:56 +0300 (EEST) Received: from cji.paris (unknown [172.16.3.159]) by srv-infra-1.infra.inf.glb.tvvideoms.com (Postfix) with ESMTP id 0B30420220; Fri, 2 Oct 2020 22:23:56 +0000 (UTC) From: Nicolas Gaullier To: ffmpeg-devel@ffmpeg.org Date: Sat, 3 Oct 2020 00:23:41 +0200 Message-Id: <20201002222346.1196-5-nicolas.gaullier@cji.paris> X-Mailer: git-send-email 2.27.0.windows.1 In-Reply-To: <20201002222346.1196-1-nicolas.gaullier@cji.paris> References: <20201002222346.1196-1-nicolas.gaullier@cji.paris> MIME-Version: 1.0 Subject: [FFmpeg-devel] [PATCH v4 4/9] avformat/s337m: New ff_s337m_probe() X-BeenThere: ffmpeg-devel@ffmpeg.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: FFmpeg development discussions and patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: FFmpeg development discussions and patches Cc: Nicolas Gaullier Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Similar to ff_spdif_probe() with just an additional checking of the bit resolution of the container as it may be 16 or 24 for s337m. --- libavformat/s337m.c | 32 ++++++++++++++++++++++++++++++++ libavformat/s337m.h | 16 ++++++++++++++++ 2 files changed, 48 insertions(+) diff --git a/libavformat/s337m.c b/libavformat/s337m.c index 790f356709..614344cd46 100644 --- a/libavformat/s337m.c +++ b/libavformat/s337m.c @@ -130,6 +130,38 @@ static int s337m_probe(const AVProbeData *p) return 0; } +int ff_s337m_probe(const uint8_t *buf, int size, enum AVCodecID *codec, int container_word_bits) +{ + int pos = 0; + int consecutive_codes = 0; + + if ( size < S337M_MIN_OFFSET) + return 0; + size = FFMIN(3 * S337M_MAX_OFFSET, size); + if (container_word_bits != 16 && container_word_bits != 24) + return AVERROR_INVALIDDATA; + + do { + uint64_t state; + int data_type, data_size, offset; + while (pos < size - 12 && !buf[pos]) { + pos++; + } + if (pos >= size - 12 || pos < S337M_PROBE_GUARDBAND_MIN_BYTES || pos % (container_word_bits == 16 ? 4 : 6)) + return 0; + state = container_word_bits == 16 ? AV_RB32(buf + pos) : AV_RB48(buf + pos); + if (!IS_LE_MARKER(state)) + return 0; + data_type = container_word_bits == 16 ? AV_RL16(buf + pos + 4) : AV_RL24(buf + pos + 6); + data_size = container_word_bits == 16 ? AV_RL16(buf + pos + 6) : AV_RL24(buf + pos + 9); + if (s337m_get_offset_and_codec(NULL, state, data_type, data_size, container_word_bits, &offset, codec)) + return 0; + pos = ++consecutive_codes * (offset + 4*(container_word_bits == 16 ? 4 : 6)); + } while (consecutive_codes < 3); + + return AVPROBE_SCORE_MAX; +} + static int s337m_read_header(AVFormatContext *s) { s->ctx_flags |= AVFMTCTX_NOHEADER; diff --git a/libavformat/s337m.h b/libavformat/s337m.h index af2c4c85a3..94e79dce5d 100644 --- a/libavformat/s337m.h +++ b/libavformat/s337m.h @@ -21,6 +21,22 @@ #ifndef AVFORMAT_S337M_H #define AVFORMAT_S337M_H +#define S337M_MIN_OFFSET 1601*4 +#define S337M_MAX_OFFSET 2002*6 + +#define S337M_PROBE_GUARDBAND_MIN_BYTES 0 + +/** + * Detect s337m packets in a PCM_S16LE/S24LE stereo stream + * Requires 3 samples with enough (S337M_PROBE_GUARDBAND_MIN_BYTES) and clean (set to zero) guard band + * @param p_buf Buffer + * @param size Buffer size + * @param codec Returns AV_CODEC_ID_DOLBY_E upon successful probing + * @param container_word_bits 16 or 24 + * @return = AVPROBE_SCORE + */ +int ff_s337m_probe(const uint8_t *p_buf, int size, enum AVCodecID *codec, int container_word_bits); + /** * Read s337m packets in a PCM_S16LE/S24LE stereo stream * Returns the first inner packet found