From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org [79.124.17.100]) by master.gitmailbox.com (Postfix) with ESMTPS id F2EF24DBB4 for ; Sat, 1 Mar 2025 14:10:35 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id B100368E12E; Sat, 1 Mar 2025 16:10:30 +0200 (EET) Received: from smtp.waider.ie (smtp.waider.ie [52.31.250.228]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 2CA1068DB94 for ; Sat, 1 Mar 2025 16:10:24 +0200 (EET) Received: from smtpclient.apple (unknown [109.255.224.49]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.waider.ie (Postfix) with ESMTPSA id 90C7D4993C for ; Sat, 1 Mar 2025 14:10:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=waider.ie; s=waider_ie; t=1740838223; bh=n7EbntNOPlYMSvEhDGSiWZRdwJfb6oSfIexN04hr1Z4=; h=Content-Type:Mime-Version:Subject:To:From:In-Reply-To:Date: Content-Transfer-Encoding:Message-Id:References; b=OeySVUaFJWd1aK1BxtonJExKiyoCOPbp9SKzaizG64ZErji9X25jYsE3poXEHjCrQ aWMDPzc7pXFEfP6taYR9tELu+WdaumPuCdATqxCtxJOqHMoY3p/doPsvhwzNFd2DX4 FTEG69no79z1R6PaM5PuwjRaBbve91C89N76M6/w= Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3826.400.131.1.6\)) To: ffmpeg-devel@ffmpeg.org From: Ronan Waide In-Reply-To: Date: Sat, 1 Mar 2025 14:10:16 +0000 Message-Id: References: Organization: Poor, at best X-Mailer: Apple Mail (2.3826.400.131.1.6) X-Spam-Status: No, score=-102.9 required=5.0 tests=ALL_TRUSTED,BAYES_00, USER_IN_WELCOMELIST,USER_IN_WHITELIST autolearn=ham autolearn_force=no version=3.4.3 X-Spam-Checker-Version: SpamAssassin 3.4.3 (2019-12-06) on ec2.waider.ie Subject: [FFmpeg-devel] [PATCH v3] libavcodec/dvbsubenc.c: add a disable_2bpp option to work around some decoders. X-BeenThere: ffmpeg-devel@ffmpeg.org X-Mailman-Version: 2.1.29 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 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: (changes from previous attempt: fixed an error in the docfile and made sure I'm diffing against origin/master) As noted in the code in several places, some DVB subtitle decoders don't handle 2bpp color. This patch adds a disable_2bpp option which disables the 2bpp format; subtitles which would use 2bpp will be bumped up to 4bpp. Signed-off-by: Ronan Waide --- doc/encoders.texi | 27 ++++++++++++++ libavcodec/dvbsubenc.c | 85 +++++++++++++++++++++++++++++++++--------- 2 files changed, 95 insertions(+), 17 deletions(-) diff --git a/doc/encoders.texi b/doc/encoders.texi index f3fcc1aa60..07984b6b54 100644 --- a/doc/encoders.texi +++ b/doc/encoders.texi @@ -4484,6 +4484,33 @@ Reduces detail but attempts to preserve color at extremely low bitrates. @chapter Subtitles Encoders @c man begin SUBTITLES ENCODERS +@section dvbsub + +This codec encodes the bitmap subtitle format that is used in DVB +broadcasts and recordings. The bitmaps are typically embedded in a +container such as MPEG-TS as a separate stream. + +@subsection Options + +@table @option +@item disable_2bpp @var{boolean} +Disable the 2 bits-per-pixel encoding format. + +DVB supports 2, 4, and 8 bits-per-pixel color lookup tables. However, +not all players support or properly support 2 bits-per-pixel, +resulting in unusable subtitles. +@table @option +@item 0 +The 2 bits-per-pixel encoding format will be used for subtitles with 4 +colors or less. (default) + +@item 1 +The 2 bits-per-pixel encoding format will be disabled, and subtitles +with 4 colors or less will use a 4 bits-per-pixel format. +@end table + +@end table + @section dvdsub This codec encodes the bitmap subtitle format that is used in DVDs. diff --git a/libavcodec/dvbsubenc.c b/libavcodec/dvbsubenc.c index 822e3a5309..727a75e901 100644 --- a/libavcodec/dvbsubenc.c +++ b/libavcodec/dvbsubenc.c @@ -22,9 +22,13 @@ #include "bytestream.h" #include "codec_internal.h" #include "libavutil/colorspace.h" +#include "libavutil/opt.h" typedef struct DVBSubtitleContext { + AVClass * class; int object_version; + int disable_2bpp; + int min_colors; } DVBSubtitleContext; #define PUTBITS2(val)\ @@ -38,6 +42,18 @@ typedef struct DVBSubtitleContext { }\ } +static int dvbsub_init(AVCodecContext *avctx) +{ + DVBSubtitleContext *s = avctx->priv_data; + if (s->disable_2bpp) { + av_log(avctx, AV_LOG_DEBUG, "Disabling 2bpp subtitles.\n"); + s->min_colors = 16; + } else { + s->min_colors = 0; + } + return 0; +} + static int dvb_encode_rle2(uint8_t **pq, int buf_size, const uint8_t *bitmap, int linesize, int w, int h) @@ -326,18 +342,22 @@ static int dvbsub_encode(AVCodecContext *avctx, uint8_t *outbuf, int buf_size, if (h->num_rects) { for (clut_id = 0; clut_id < h->num_rects; clut_id++) { - if (buf_size < 6 + h->rects[clut_id]->nb_colors * 6) + int nb_colors = s->min_colors > h->rects[clut_id]->nb_colors + ? s->min_colors + : h->rects[clut_id]->nb_colors; + + if (buf_size < 6 + nb_colors * 6) return AVERROR_BUFFER_TOO_SMALL; /* CLUT segment */ - if (h->rects[clut_id]->nb_colors <= 4) { + if (nb_colors <= 4) { /* 2 bpp, some decoders do not support it correctly */ bpp_index = 0; - } else if (h->rects[clut_id]->nb_colors <= 16) { + } else if (nb_colors <= 16) { /* 4 bpp, standard encoding */ bpp_index = 1; - } else if (h->rects[clut_id]->nb_colors <= 256) { + } else if (nb_colors <= 256) { /* 8 bpp, standard encoding */ bpp_index = 2; } else { @@ -354,16 +374,24 @@ static int dvbsub_encode(AVCodecContext *avctx, uint8_t *outbuf, int buf_size, *q++ = clut_id; *q++ = (0 << 4) | 0xf; /* version = 0 */ - for(i = 0; i < h->rects[clut_id]->nb_colors; i++) { + for(i = 0; i < nb_colors; i++) { *q++ = i; /* clut_entry_id */ *q++ = (1 << (7 - bpp_index)) | (0xf << 1) | 1; /* 2 bits/pixel full range */ { int a, r, g, b; - uint32_t x= ((uint32_t*)h->rects[clut_id]->data[1])[i]; - a = (x >> 24) & 0xff; - r = (x >> 16) & 0xff; - g = (x >> 8) & 0xff; - b = (x >> 0) & 0xff; + if (i < h->rects[clut_id]->nb_colors) { + uint32_t x= ((uint32_t*)h->rects[clut_id]->data[1])[i]; + a = (x >> 24) & 0xff; + r = (x >> 16) & 0xff; + g = (x >> 8) & 0xff; + b = (x >> 0) & 0xff; + } else { + /* pad out the CLUT */ + a = 0; + r = 0; + g = 0; + b = 0; + } *q++ = RGB_TO_Y_CCIR(r, g, b); *q++ = RGB_TO_V_CCIR(r, g, b, 0); @@ -373,7 +401,7 @@ static int dvbsub_encode(AVCodecContext *avctx, uint8_t *outbuf, int buf_size, } bytestream_put_be16(&pseg_len, q - pseg_len - 2); - buf_size -= 6 + h->rects[clut_id]->nb_colors * 6; + buf_size -= 6 + nb_colors * 6; } if (buf_size < h->num_rects * 22) @@ -381,14 +409,17 @@ static int dvbsub_encode(AVCodecContext *avctx, uint8_t *outbuf, int buf_size, for (region_id = 0; region_id < h->num_rects; region_id++) { /* region composition segment */ + int nb_colors = s->min_colors > h->rects[region_id]->nb_colors + ? s->min_colors + : h->rects[region_id]->nb_colors; - if (h->rects[region_id]->nb_colors <= 4) { + if (nb_colors <= 4) { /* 2 bpp, some decoders do not support it correctly */ bpp_index = 0; - } else if (h->rects[region_id]->nb_colors <= 16) { + } else if (nb_colors <= 16) { /* 4 bpp, standard encoding */ bpp_index = 1; - } else if (h->rects[region_id]->nb_colors <= 256) { + } else if (nb_colors <= 256) { /* 8 bpp, standard encoding */ bpp_index = 2; } else { @@ -424,17 +455,21 @@ static int dvbsub_encode(AVCodecContext *avctx, uint8_t *outbuf, int buf_size, const uint8_t *bitmap, int linesize, int w, int h); + int nb_colors = s->min_colors > h->rects[object_id]->nb_colors + ? s->min_colors + : h->rects[object_id]->nb_colors; + if (buf_size < 13) return AVERROR_BUFFER_TOO_SMALL; /* bpp_index maths */ - if (h->rects[object_id]->nb_colors <= 4) { + if (nb_colors <= 4) { /* 2 bpp, some decoders do not support it correctly */ dvb_encode_rle = dvb_encode_rle2; - } else if (h->rects[object_id]->nb_colors <= 16) { + } else if (nb_colors <= 16) { /* 4 bpp, standard encoding */ dvb_encode_rle = dvb_encode_rle4; - } else if (h->rects[object_id]->nb_colors <= 256) { + } else if (nb_colors <= 256) { /* 8 bpp, standard encoding */ dvb_encode_rle = dvb_encode_rle8; } else { @@ -506,6 +541,20 @@ static int dvbsub_encode(AVCodecContext *avctx, uint8_t *outbuf, int buf_size, return q - outbuf; } +#define OFFSET(x) offsetof(DVBSubtitleContext, x) +#define SE AV_OPT_FLAG_SUBTITLE_PARAM | AV_OPT_FLAG_ENCODING_PARAM +static const AVOption options[] = { + {"disable_2bpp", "disable the 2bpp subtitle encoder", OFFSET(disable_2bpp), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, SE}, + { NULL }, +}; + +static const AVClass dvbsubenc_class = { + .class_name = "DVBSUB subtitle encoder", + .item_name = av_default_item_name, + .option = options, + .version = LIBAVUTIL_VERSION_INT, +}; + const FFCodec ff_dvbsub_encoder = { .p.name = "dvbsub", CODEC_LONG_NAME("DVB subtitles"), @@ -513,4 +562,6 @@ const FFCodec ff_dvbsub_encoder = { .p.id = AV_CODEC_ID_DVB_SUBTITLE, .priv_data_size = sizeof(DVBSubtitleContext), FF_CODEC_ENCODE_SUB_CB(dvbsub_encode), + .init = dvbsub_init, + .p.priv_class = &dvbsubenc_class, }; -- 2.39.5 (Apple Git-154) _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".